new alty and battery, but still fading lights??
11-12-2007, 05:34 PM
#1
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new alty and battery, but still fading lights??
Hey all, I just replaced my dying alty with a new duralast and yellow top optima....however something is still draining the battery under higher than normal loads. For example, if I try to roll up the window even though it is all the way up, the lights will dim. Also, if I turn up the radio too loud the lights dim when the bass hits. Anyone know what else to replace/check???
On a side note, perhaps related, when I rev the engine while in neutral, then take my foot off the pedal, the rpms rise and fall as normal but dip a few hundred below the idle speed, then quicky correct and the car will idle as it should. What could cause this slight quick dip in idle speed while the rpms are falling? Is it related to the dimming lights? Thanks for the help!
On a side note, perhaps related, when I rev the engine while in neutral, then take my foot off the pedal, the rpms rise and fall as normal but dip a few hundred below the idle speed, then quicky correct and the car will idle as it should. What could cause this slight quick dip in idle speed while the rpms are falling? Is it related to the dimming lights? Thanks for the help!
11-12-2007, 05:41 PM
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dimming lights? I mean, it still dims if the windows are down and I roll them up.... basically any higher load will dim the lights. I feel like my entire car needs a capacitor, lol.
11-12-2007, 05:42 PM
#4
For the dimming part, I think you should make sure all your grounds are free of rust/corrosion. Also I suggest you check your alternator with a multimeter while your car is idling and it should register at least 14volts, also test battery with meter while car is off and should be at least 12.xx volts. If its any lower than those numbers for either batt or alty, you should get it tested at idiotzone.
Another thing I can thing of that causes the dimming is that the window motor is old and is drawing more power than it should. System once again I think might have a bad ground.
My Idle dips just like yours for some reason. What could it be?
Another thing I can thing of that causes the dimming is that the window motor is old and is drawing more power than it should. System once again I think might have a bad ground.
My Idle dips just like yours for some reason. What could it be?
11-12-2007, 05:43 PM
#5
11-12-2007, 06:52 PM
#7
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agreed! If you have a stereo system, get a capacitor so that the additional power surge from your amp doesn't bog down your alternator. Overtime this inrush current may compromise your new alternator, as it is obviously being over exerted. (btw mine has been like this for 2 years or so, and still kicking)
As for the power windows, dont worry about it, mine have done this forever. No big deal. Obviously your windows are not designed to be rolled up past the frame. Its kind of like saying "when I drive in reverse at 10 mph then put the transmission in drive, my car makes a funny sound" the vehicle is not meant to operate this way, so it is not unusual for it to exibit less than desirable symtoms. I believe this is completely normal for the car, and have had several vehicles that did the same thing.
Don't worry about Blootoof, not everyones maxima is exceptionally perfect. I disagree with his bad ground theory, but what do I know, maybe he has a degree in Electrical/Electronics Engineering...........oh wait, I have one of those.
All in good fun Blootoof take it easy.
As for the power windows, dont worry about it, mine have done this forever. No big deal. Obviously your windows are not designed to be rolled up past the frame. Its kind of like saying "when I drive in reverse at 10 mph then put the transmission in drive, my car makes a funny sound" the vehicle is not meant to operate this way, so it is not unusual for it to exibit less than desirable symtoms. I believe this is completely normal for the car, and have had several vehicles that did the same thing.
Don't worry about Blootoof, not everyones maxima is exceptionally perfect. I disagree with his bad ground theory, but what do I know, maybe he has a degree in Electrical/Electronics Engineering...........oh wait, I have one of those.
All in good fun Blootoof take it easy.
Last edited by Sevorg1; 11-12-2007 at 07:21 PM.
11-12-2007, 07:48 PM
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Overtime this inrush current may compromise your new alternator, as it is obviously being over exerted.
If the alt cannot handle the car's setup, fitting a cap will definitely kill the alt because the cap has an infinitely lower internal resistance than ANY load the car can stick on the electrical system (with the possible exception of the starter).
Fitting a cap is effectively hiding the presence of bad connections or too thin a guage of wire to the load etc etc
I disagree with his bad ground theory, but what do I know, maybe he has a degree in Electrical/Electronics Engineering...........oh wait, I have one of those.
11-12-2007, 08:11 PM
#9
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Now that is a plain crock ................. what do you think charges the capacitor?
If the alt cannot handle the car's setup, fitting a cap will definitely kill the alt because the cap has an infinitely lower internal resistance than ANY load the car can stick on the electrical system (with the possible exception of the starter).
Fitting a cap is effectively hiding the presence of bad connections or too thin a guage of wire to the load etc etc If that is a fact, I suggest you get a refund while you can then.
If the alt cannot handle the car's setup, fitting a cap will definitely kill the alt because the cap has an infinitely lower internal resistance than ANY load the car can stick on the electrical system (with the possible exception of the starter).
Fitting a cap is effectively hiding the presence of bad connections or too thin a guage of wire to the load etc etc If that is a fact, I suggest you get a refund while you can then.
The capacitor charges off of the battery and only discharges once the load cannot be handled
by the battery, the alternator charges the battery. they work in unison.<----spelling A capacitor wont kill your altenator unless it was just the altenator and the cap, and the cap was constantly being discharged past the abilities of the alt.
dont get the impression that capacitors are bad. A capacitor is the proper way to fix this problem for the application. If it weren't then they wounldnt make them for just this purpose. I hope that he didn't put in too small of a wire. Most wiring kits come with a fuse, that I would hope would blow if the load was too great for the gauge of wire. this is assuming you didnt replace your fuse with a bigger one or buy some cheap kit that was not properly engineered
no harm no foul thanks for your opinion of my education. I'll do what I can to get my money back
Last edited by Sevorg1; 11-12-2007 at 08:54 PM.
11-12-2007, 09:40 PM
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thanks for crashing my party. my main point though was that not a bad ground.
Stating that you have an Electrical/Electronic Engineering degree does not make that a fact - especially when you start propagating rubbish like what you posted here.
Bad grounds and inadeguate wire guage can and will have exactly the same effect in a typical vehicle - it has to do with series resistance added to the load you are trying to drive and the associated voltage drop experienced on the load - if your "degree" never taught you about this, use Google to look up those terms individually before posting nonsense under the guise of a simple misunderstanding.
Further:
The capacitor charges off of the battery and only discharges once the load cannot be handled
by the battery, the alternator charges the battery. they work in unison
by the battery, the alternator charges the battery. they work in unison
Most wiring kits come with a fuse, that I would hope would blow if the load was too great for the gauge of wire. this is assuming you didnt replace your fuse with a bigger one or buy some cheap kit that was not properly engineered
Fuses are safety devices and are sized according to the expected load it supplies - it's rating and application has absolutely nothing to do with the gauge of wire used to supply the load - they blow when the current exceeds its normally expected current consumption for a certain period of time irrespective of wire gauge used .........................
Please stop spewing forth untruths under the guise that you are an engineer - you are making a mockery of my profession while hiding behind the anonymity the INTERNET affords you on a forum like this.
11-12-2007, 10:49 PM
#11
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can we limit the personal bashing?* this doesn't help anyone and get's no one anywhere.+1 on getting the alternator tested.* If you can I would take it to a shop, most will do it for free.* I have had a few cars that had a bad alternator and had Autozone test them and say they were ok and within spec.* My buddy owns a shop and WILL NOT use any electrical product from Autozone (starters, alternators, etc) too many times a new one was put on to have a customer return the next day with a failed part.* I'd reccomend a Bosch or Visteon.* When you have the alternator tested, like said above make sure they do a load test.
11-12-2007, 11:45 PM
#12
Hey Sevorg1, he never did mention that his lights dimmed when he went passed the frame...he just mentioned that they dimmed WHILE it was going up but not forcing it past it limit, that was me that mentioned that it was the only time mine would cause the lights to dim.
As for Electric/Electronics Engineering, I do not have a degree so you do have that advantage over me. I was just suggesting what seemed obvious from the little I know. If you dont mind me asking, where did you get your degree? I was planning on going for IEEE(think thats it) but I suck at math.
My car isnt quite perfect either, I'm working on it though
As for Electric/Electronics Engineering, I do not have a degree so you do have that advantage over me. I was just suggesting what seemed obvious from the little I know. If you dont mind me asking, where did you get your degree? I was planning on going for IEEE(think thats it) but I suck at math.
My car isnt quite perfect either, I'm working on it though
11-13-2007, 08:35 AM
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welllll....I'm currently in school for my ME degree, and while my knowledge of electronics theory and physics is limited, my skill to design and fix electronic systems is not. I am fairly certain that I do not have a bad ground anywhere in the car. The alternator is new, but I will have to take it to a shop to get it load tested. Duramax is a shoddy brand, even in my opinion, but the lifetime warranty is obviously what attracted me. It's an EASY part to replace, so I don't mind it. If it were a waterpump or something both more vital/difficult to replace...I'd surely go with a Bosch or Nissan part.
LvR and Sevorg1....in all that conversation was there a reccomendation as to what the problem could be? Degrees aside, I was never going to install a capacitor anywhere in the system to fix this problem. My comment was made jokingly, and should be taken as such. As I said before, the wiring on the car, while done by myself, is perfectly adequate for the application. An 8awg power and ground wire is adequate for a small 150 watt amp, and the 4awg wire going into the trunk is not even connected to anything at the moment. Essentially I just have a small amp and HU connected directly to the battery, both with dedicated grounds that are connected directly to the chassis.
LvR and Sevorg1....in all that conversation was there a reccomendation as to what the problem could be? Degrees aside, I was never going to install a capacitor anywhere in the system to fix this problem. My comment was made jokingly, and should be taken as such. As I said before, the wiring on the car, while done by myself, is perfectly adequate for the application. An 8awg power and ground wire is adequate for a small 150 watt amp, and the 4awg wire going into the trunk is not even connected to anything at the moment. Essentially I just have a small amp and HU connected directly to the battery, both with dedicated grounds that are connected directly to the chassis.
11-13-2007, 09:44 AM
#14
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While I am surely to blame for the OT posts, the answers are present, and have to do with voltage drop measurements under load.
1. Have a fully charged battery ready (overnight on charger), start the car and measure the voltage between the alternator output terminal (not anywhere else) and the body of the alternator with the motor doing around 2500rpm - you should see somewhere around 14V when the motor is cold.
2. Is the measurement on the battery terminals the same to within 0.1V as in #1?
3. Switch on your lights and with the motor still doing around 2500rpm, measure between the body of the alt and the negative terminal of the battery, and also between the alternator output terminal (directly) and the positive terminal of the battery - in both cases it should be under 0.2V and preferably lower.
4.Same conditions as in #3 but measure on the actual globe terminals - is that voltage the same as you measure on the alternator output terminal and body? - to within about 0.5V?
If #1 is not so you have a alternator problem.
If any of the answers to 2,3, and 4 are no, then you have earth quality problems, inadequate cable capacity (by design or due to age) or poor terminal connection quality.
Come back with measurements and answers and perhaps we can take it further - depending on your results here it could turn into a complex (ito only figuring where and when to measure voltages) faultfinding exercise.
1. Have a fully charged battery ready (overnight on charger), start the car and measure the voltage between the alternator output terminal (not anywhere else) and the body of the alternator with the motor doing around 2500rpm - you should see somewhere around 14V when the motor is cold.
2. Is the measurement on the battery terminals the same to within 0.1V as in #1?
3. Switch on your lights and with the motor still doing around 2500rpm, measure between the body of the alt and the negative terminal of the battery, and also between the alternator output terminal (directly) and the positive terminal of the battery - in both cases it should be under 0.2V and preferably lower.
4.Same conditions as in #3 but measure on the actual globe terminals - is that voltage the same as you measure on the alternator output terminal and body? - to within about 0.5V?
If #1 is not so you have a alternator problem.
If any of the answers to 2,3, and 4 are no, then you have earth quality problems, inadequate cable capacity (by design or due to age) or poor terminal connection quality.
Come back with measurements and answers and perhaps we can take it further - depending on your results here it could turn into a complex (ito only figuring where and when to measure voltages) faultfinding exercise.
11-13-2007, 09:53 AM
#15
DO THE BIG THE 3...that will help with the dimming lights...there are plenty or write ups on here on how to do it....if you don't want to do that get a bat cap....it better than a reg capacitor...good luck...also check your alternator
11-13-2007, 09:55 AM
#16
Regardless of degree's, all I'm saying is that it shouldn't be a huge concern, and if it really does bother you, you can always go to Home Depot and get some thick gauge wire and re-do/ add on to your ground kit in the engine bay.
11-13-2007, 10:06 AM
#18
11-13-2007, 10:10 AM
#19
I agree with LvR.. Most likely you have a bad ground or power cable somewhere, or simply a dirty connection. Another culprit to look at is a possibly blown/damaged Fusible link.
The relatively small window motors and things like that are a tiny load on the system- only a fraction of what it should output, so your lights should not dim at all by window motors or the A/C fans on high. Any stereo under 600W should not dim the headlights when turned up either. If you have one larger than about 600W, then a 1F electrolytic capacitor is a good idea. (stay away from those 50F "batcaps" and junk like that. they're not the right type of capacitor and only add more problems to an already strained electrical system. (I'm running a 2F cap & Optima Yellow top on my 2500W system and have no dimming lights at full volume, even with the engine off.)
Back to the point of discussion...........
It could also be the reman alternator. The places that rebuild them simply find the blown up part and replace it, clean the case, and reassemble it. they don't fully troubleshoot and repair the alternator thoroughly before repacking it and shipping it to the parts stores. One time I got THREE bad VG alternators in a row from the parts store. For future reference, I HIGHLY recommend having the "new" alternator tested on their machine at the store before installing it in the car.
What kind of battery terminals are you running? Are they clamped tight to a clean battery post? are the wires clean and properly terminated into said battery connector?
If you're still using the OEM original battery "terminals", cut them off and throw them away. they're 15 years old and were marginal to begin with. after 15+years of corrosion and having been installed/removed dozens of times by now, they're below par and need to be replaced with better quality terminals.
If you're using the $3 painted terminals you get at a parts store, take them apart and use a dremel or something to grind the paint off underneath the clamp where it makes direct contact with the wire. Then put some dielectric grease over it after you clean the cable to protect it from corrosion.
Check your engine-frame-battery grounds. there's a 4awg wire that goes from the battery's (-) terminal to the chassis just under the battery tray, then extends to the engine ground bracket. ALL of these connections need to be clean and corrosion free.
you can't just look at the +12v wire going from the alt to the battery, as LvR explained. There are many other connections and cables that could be the culprit. You must look at them ALL in order to make a proper diagnosis.
and yes.. I have a degree in Electrical Engineering. I specialized in high power electronics and power distribution. Feel free to try to shoot holes in anything myself or LvR said, and I can keep up with the best of you any day of the week.
The relatively small window motors and things like that are a tiny load on the system- only a fraction of what it should output, so your lights should not dim at all by window motors or the A/C fans on high. Any stereo under 600W should not dim the headlights when turned up either. If you have one larger than about 600W, then a 1F electrolytic capacitor is a good idea. (stay away from those 50F "batcaps" and junk like that. they're not the right type of capacitor and only add more problems to an already strained electrical system. (I'm running a 2F cap & Optima Yellow top on my 2500W system and have no dimming lights at full volume, even with the engine off.)
Back to the point of discussion...........
It could also be the reman alternator. The places that rebuild them simply find the blown up part and replace it, clean the case, and reassemble it. they don't fully troubleshoot and repair the alternator thoroughly before repacking it and shipping it to the parts stores. One time I got THREE bad VG alternators in a row from the parts store. For future reference, I HIGHLY recommend having the "new" alternator tested on their machine at the store before installing it in the car.
What kind of battery terminals are you running? Are they clamped tight to a clean battery post? are the wires clean and properly terminated into said battery connector?
If you're still using the OEM original battery "terminals", cut them off and throw them away. they're 15 years old and were marginal to begin with. after 15+years of corrosion and having been installed/removed dozens of times by now, they're below par and need to be replaced with better quality terminals.
If you're using the $3 painted terminals you get at a parts store, take them apart and use a dremel or something to grind the paint off underneath the clamp where it makes direct contact with the wire. Then put some dielectric grease over it after you clean the cable to protect it from corrosion.
Check your engine-frame-battery grounds. there's a 4awg wire that goes from the battery's (-) terminal to the chassis just under the battery tray, then extends to the engine ground bracket. ALL of these connections need to be clean and corrosion free.
you can't just look at the +12v wire going from the alt to the battery, as LvR explained. There are many other connections and cables that could be the culprit. You must look at them ALL in order to make a proper diagnosis.
and yes.. I have a degree in Electrical Engineering. I specialized in high power electronics and power distribution. Feel free to try to shoot holes in anything myself or LvR said, and I can keep up with the best of you any day of the week.
11-13-2007, 10:11 AM
#20
heh.. those pics above look familiar....
FYI, that's not the "big 3" though. look in the audio forum for a proper explanation of the big 3... or howstuffworks.com probably has a nice explanation as well. or any car audio site....
FYI, that's not the "big 3" though. look in the audio forum for a proper explanation of the big 3... or howstuffworks.com probably has a nice explanation as well. or any car audio site....
11-13-2007, 10:37 AM
#22
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This may have been beaten to death, but I have to throw in my two cents about cap's. Capacitors are basically useless for the problems you are having. The idea behind them is that when there is a large current draw from your amp, and your alternator and battery can't handle it, the cap will supply the current. The truth of the matter is that never happens.
You can read a TON of great information about Caps at http://forum.realmofexcursion.com/sh...ad.php?t=17970
The short of it is this: more than half the energy stored in a capacitor can only be used if the system voltage drops below 10 volts. Below 10 volts, your battery will be nearly dead, and your stereo will shut down. When your engine is running, your system voltage is held at 14.2 volts.
As long as the voltage in the battery / alternator system is higher than the voltage in the cap, the cap will be drawing power from the battery alternator, until they are at the same voltage. If the voltage in the alternator / battery system is LOWER than the voltage in the cap, then current will flow from the cap into the battery / amp.
Current NEVER flows into the alternator, even if it is at a lower voltage than the battery / cap because there are diodes in the alternator to prevent that from happening.
When your amp hits that big bass note, and tries to draw more current than your alternator can handle, the voltage at the alternator drops. Since your capacitor is charged to the same 14.2 volts that the alternator maintains, it tries to supply the needed current, however due to internal resistance, and capacitance, there is a voltage drop inside the capacitor, which tries to drop the internal voltage of the capacitor. The exact voltage that the capacitor tries to drop to depends on the capacitor, and the current your amp tries to draw off it, but generally speaking it is going to be somewhere in the 9 to 11 volt range. This happens instantly. Because your battery is at 12.8 volts, as soon as the voltage in the capacitor drops below 12.8 (and that happens INSTANTLY, as soon as the alternator voltage drops below 14.2) the battery takes over, not only supplying the current needed by the amplifier, but also charging the capacitor back up.
Don't waste the money on capacitors!
BTW, anyone who claims that capacitors are the way to solve this problem, AND claims to have a degree in electronics is either full of pooh, or purchased their degree instead of earning it. Read the article in the link above, and whip out Ohm's law (one of the first things you learn when you study electronics) and do the calculations yourself, and you will see the light.
You can read a TON of great information about Caps at http://forum.realmofexcursion.com/sh...ad.php?t=17970
The short of it is this: more than half the energy stored in a capacitor can only be used if the system voltage drops below 10 volts. Below 10 volts, your battery will be nearly dead, and your stereo will shut down. When your engine is running, your system voltage is held at 14.2 volts.
As long as the voltage in the battery / alternator system is higher than the voltage in the cap, the cap will be drawing power from the battery alternator, until they are at the same voltage. If the voltage in the alternator / battery system is LOWER than the voltage in the cap, then current will flow from the cap into the battery / amp.
Current NEVER flows into the alternator, even if it is at a lower voltage than the battery / cap because there are diodes in the alternator to prevent that from happening.
When your amp hits that big bass note, and tries to draw more current than your alternator can handle, the voltage at the alternator drops. Since your capacitor is charged to the same 14.2 volts that the alternator maintains, it tries to supply the needed current, however due to internal resistance, and capacitance, there is a voltage drop inside the capacitor, which tries to drop the internal voltage of the capacitor. The exact voltage that the capacitor tries to drop to depends on the capacitor, and the current your amp tries to draw off it, but generally speaking it is going to be somewhere in the 9 to 11 volt range. This happens instantly. Because your battery is at 12.8 volts, as soon as the voltage in the capacitor drops below 12.8 (and that happens INSTANTLY, as soon as the alternator voltage drops below 14.2) the battery takes over, not only supplying the current needed by the amplifier, but also charging the capacitor back up.
Don't waste the money on capacitors!
BTW, anyone who claims that capacitors are the way to solve this problem, AND claims to have a degree in electronics is either full of pooh, or purchased their degree instead of earning it. Read the article in the link above, and whip out Ohm's law (one of the first things you learn when you study electronics) and do the calculations yourself, and you will see the light.
Last edited by Tquick; 11-13-2007 at 10:46 AM.
11-13-2007, 04:40 PM
#23
When your amp hits that big bass note, and tries to draw more current than your alternator can handle, the voltage at the alternator drops. Since your capacitor is charged to the same 14.2 volts that the alternator maintains, it tries to supply the needed current, however due to internal resistance, and capacitance, there is a voltage drop inside the capacitor, which tries to drop the internal voltage of the capacitor. The exact voltage that the capacitor tries to drop to depends on the capacitor, and the current your amp tries to draw off it, but generally speaking it is going to be somewhere in the 9 to 11 volt range. This happens instantly. Because your battery is at 12.8 volts, as soon as the voltage in the capacitor drops below 12.8 (and that happens INSTANTLY, as soon as the alternator voltage drops below 14.2) the battery takes over, not only supplying the current needed by the amplifier, but also charging the capacitor back up.
Don't waste the money on capacitors!
Don't waste the money on capacitors!
The internal resistance of the capacitor affects its maximum current output and its overall efficiency in the grand scheme of things. the job of a capacitor in this case is to store and dump energy-quickly. they can be used for many other things as well, but this case is simply to store energy and stabilize the voltage on the line. the internal capacitance of a capacitor is an oxymoron- it's a capacitor! It's supposed to have internal capacitance!
(you may be trying to reference inductance???) again doesn't have much bearing on this discussion.
The capacitor drops its voltage (as well as the rest of the electrical system, given proper wiring) based on the amount of energy the load (amplifiers) is trying to shove out to the speakers.
V = I*t/C
V= volts
I = current (A)
t= time (sec)
C= capacitance (F)
No part of the system INSTANTLY drops voltage from 14v to 9 v. it's a gradual drop, based on the system's total energy output and storage capability. It's not JUST the alternator or battery or capacitor or wiring. It all has to be taken into account as a system. Again, its pointless in this thread, as the problems mentioned in the original post are well into what the stock electrical system should be able to handle without breaking a sweat.
11-13-2007, 07:25 PM
#24
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My assumed ESR for the caps was .017. Even if none of the math was flawed, current caps have an ESR rating more like .00175, which would blow my argument away, so I will demonstrate that I am man enough to say I was completely wrong. A little knowledge is a dangerous thing.
At any rate, the stereo shouldn't be making the lights dim if the alternator is in good shape, and all the wiring is good. I've got somewhere around 800 watts in my car, stock alternator, and the lights don't dim a bit, even on the loudest thumps.
At any rate, the stereo shouldn't be making the lights dim if the alternator is in good shape, and all the wiring is good. I've got somewhere around 800 watts in my car, stock alternator, and the lights don't dim a bit, even on the loudest thumps.
11-13-2007, 08:18 PM
#25
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I never bashed anyone. Yes I have an EE degree. Never said I am an active EE I do more specialized work. Instrumentation automation and control. Capacitors do have there place in a large stereo system. I suppose that we will have to continue to disagree.
To defend my statement the gauge of the wire is selected based off what the load will be or how many amps the load will pull. I know the purpose of fuses for overcurrent protection. the idea is that one would not use a huge 100 amp fuse with a very small wire. This would make me say that your gauge of wire is relative to the size of overcurrent protection thus they are related. Im not out to prove anything, if you disagree you may say so, but in my opinion to bash is childish, unprofessional, and defeates the purpose of the forum.
I said the cap charges from the battery and alternator hence they work in unison, never did I say to place the cap next to the battery. we are obviously having a failure to communicate if thats what was understood.
Yes bad wiring and connections can cause the problems that were originally listed.
a 150 watt amp should not cause this problem
Sorry for trying to help. sorry if the conversation was deemed off topic by the powers that be
To defend my statement the gauge of the wire is selected based off what the load will be or how many amps the load will pull. I know the purpose of fuses for overcurrent protection. the idea is that one would not use a huge 100 amp fuse with a very small wire. This would make me say that your gauge of wire is relative to the size of overcurrent protection thus they are related. Im not out to prove anything, if you disagree you may say so, but in my opinion to bash is childish, unprofessional, and defeates the purpose of the forum.
I said the cap charges from the battery and alternator hence they work in unison, never did I say to place the cap next to the battery. we are obviously having a failure to communicate if thats what was understood.
Yes bad wiring and connections can cause the problems that were originally listed.
a 150 watt amp should not cause this problem
Sorry for trying to help. sorry if the conversation was deemed off topic by the powers that be
Last edited by Sevorg1; 11-13-2007 at 09:02 PM.
11-14-2007, 01:14 AM
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yeah, it'll be a couple days untill I get some time to test stuff with my dmm. Besides the fact that it's freezing-*** cold, I have a ton of work this week for school. Plus this weekend is the IU-Purdue game, so I'll be in Bloomington. I'll try to get it done over t-giving break.
11-14-2007, 06:19 AM
#28
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Join Date: Jan 2007
Posts: 179
Wire gauge should be selected based on it's ability to handle the expected current load. The problem is that I would bet MOST people who are installing stereo equipment haven't got a clue what gauge wire will handle what current. Even if they do know enough to look it up, most wouldn't be aware that if you use more than 8 or 10 feet of wire in the circuit, you need to step up to the next wire gauge to handle the same amount of current. Because of this, I would guess that there are a good many amp systems out there with fuses that are way too large to properly protect the wiring.
Last edited by Tquick; 11-14-2007 at 06:32 AM.
11-14-2007, 03:42 PM
#30
11-14-2007, 07:45 PM
#31
Senior Member
Join Date: Oct 2004
Location: Pretoria - South Africa
Posts: 1,205
11-15-2007, 08:38 PM
#33
Newbie - Just Registered
Join Date: Jan 2007
Posts: 2
Maybe ?
Hi fellas
I noticed in his mods section ' voltage regulator '
If this is so there is a possibility it's wired in a configurtation I would call machine sensed (or sensed at the alternator with no consideration of voltage drop) rather than the usual battery sensed.
If this is so then things will tend to dim a little more than accustomed due to voltage drop between the alternator and the load.
Therefore a easy fix is to confirm if the alternator is machine or battery sensed, put your voltmeter on the battery with the headlights and heater fan on high and hold about 1500 or more rpm for a minute and observe the voltmeter, if battery sensed then should be around the 14.5 ish mark.
A easy test to discover if your alternator has enuf grunt
start with a fully charged known good battery
check fan belt is tight
hold engine revs at 1500rpm +
wait a couple of minutes for the voltage to stabilise
observe the voltmeter ,it should stay stable. If slowly dropping then alternator or alt to batt wiring is too small.
I always put my hand on the side of the alternator where the laminated section is, If I cant hold my fingers there for 2 or more seconds then the alternator is too hot and wont last, Nissan have Hitachi alternators and the rectifier diodes are a known weakness and will die eventually.
another way I use to check for poor connection in a higher current situation such as headlight, windows or heater is to feel the connections, A poor higher resistance connection will usually be warmer than the surroundings.
Any queries ? go for it
I've used caps on high powered sytems , all fine, still remember to fuse the cap!
another cheaper option than a huge 2 farad+ cap is a 18a/hr sealed lead acid battery, I've done this too keeping a aftermarket fuel injection controller alive as it was dying duuring crank and wouldn't start, worked a treat
I've also used it on a party bus next to the 2x 600w rms amps
the more drunk they get the louder they like it !
Donald
New Zealand
I noticed in his mods section ' voltage regulator '
If this is so there is a possibility it's wired in a configurtation I would call machine sensed (or sensed at the alternator with no consideration of voltage drop) rather than the usual battery sensed.
If this is so then things will tend to dim a little more than accustomed due to voltage drop between the alternator and the load.
Therefore a easy fix is to confirm if the alternator is machine or battery sensed, put your voltmeter on the battery with the headlights and heater fan on high and hold about 1500 or more rpm for a minute and observe the voltmeter, if battery sensed then should be around the 14.5 ish mark.
A easy test to discover if your alternator has enuf grunt
start with a fully charged known good battery
check fan belt is tight
hold engine revs at 1500rpm +
wait a couple of minutes for the voltage to stabilise
observe the voltmeter ,it should stay stable. If slowly dropping then alternator or alt to batt wiring is too small.
I always put my hand on the side of the alternator where the laminated section is, If I cant hold my fingers there for 2 or more seconds then the alternator is too hot and wont last, Nissan have Hitachi alternators and the rectifier diodes are a known weakness and will die eventually.
another way I use to check for poor connection in a higher current situation such as headlight, windows or heater is to feel the connections, A poor higher resistance connection will usually be warmer than the surroundings.
Any queries ? go for it
I've used caps on high powered sytems , all fine, still remember to fuse the cap!
another cheaper option than a huge 2 farad+ cap is a 18a/hr sealed lead acid battery, I've done this too keeping a aftermarket fuel injection controller alive as it was dying duuring crank and wouldn't start, worked a treat
I've also used it on a party bus next to the 2x 600w rms amps
the more drunk they get the louder they like it !
Donald
New Zealand
11-15-2007, 10:21 PM
#34
Senior Member
Join Date: Oct 2004
Location: Pretoria - South Africa
Posts: 1,205
Donald
I can only speak from experience on our local South African Maximas, and here we have Bosch alternators fitted as std equipment - these animals all have the reg built into the alt and therefore effectively sensing voltage present on the output terminal of the alt (machine sensed ito your definitions) - I don't know if any of the other Maxima markets used anything other than machine sensed setups irrespective of the alt brand fitted as std equipment there, but I suspect not (looking at a sorta std FSM for all markets).
Depending on your regulator manufacturer and their design logic , your testing method may or may not work. On our Bosch units for example, when the alt is cold and you start the motor, the regulator runs around 14.1V (alt output terminal) - once the motor (alt) is warm, the alt output voltage drops to 13.6V and then stays there irrespective of load (as long as load current within specs of alt). I have tried to query this from Bosch, but got nowhere at all because none of their technical boffin wants to talk serious design parameters. Somehow this seems to go contrary to what one would expect, but talking to lead/acid battery manufacturers and looking at their suggested operating conditions, it would seem that their definition of "standby use" is basically what we have in a typical vehicle with an electrical system in good condition ................. and most of these guys recommend keeping a fully charged battery at around 13.7V (just below a typical point where lots of gas starts forming during charging) when in "standby use" - I guess Bosch may have been using the same logic in our regulator designs, and given my vehicle's own electrical performance and the absence of "dimming" lights syndrome when other loads are switched I must say ito of simplicity its probably more than adequate.
While I agree that "load voltage sensing" is probably the ultimate when looking after the performance of the load and its requirements, I feel that its probably not the correct thing to do on a typical vehicle with funky earths/connections etc etc etc. The problem imo is defining what the "load" to be sensed is going to be - if you choose the battery (that I would suggest) you still have to assume that the wiring on the vehicle is in 100% condition with no bad connections anywhere in order to really benefit from the extra complexity. Any bad connection or too small a wire gauge on any of the small vehicle loads feeding off the battery, will bring you right back to the OP's situation.
I still think my earlier recipe will be able to identify the real culprits once the OP comes back with actual initial measurements - irrespective of reg setup used
As for your temp of the alt touch test - I must be a sissy - if my engine is at normal op temp, there is no way I am going to be feeling-up my alt for anything more than probably only part of a second.
I can only speak from experience on our local South African Maximas, and here we have Bosch alternators fitted as std equipment - these animals all have the reg built into the alt and therefore effectively sensing voltage present on the output terminal of the alt (machine sensed ito your definitions) - I don't know if any of the other Maxima markets used anything other than machine sensed setups irrespective of the alt brand fitted as std equipment there, but I suspect not (looking at a sorta std FSM for all markets).
Depending on your regulator manufacturer and their design logic , your testing method may or may not work. On our Bosch units for example, when the alt is cold and you start the motor, the regulator runs around 14.1V (alt output terminal) - once the motor (alt) is warm, the alt output voltage drops to 13.6V and then stays there irrespective of load (as long as load current within specs of alt). I have tried to query this from Bosch, but got nowhere at all because none of their technical boffin wants to talk serious design parameters. Somehow this seems to go contrary to what one would expect, but talking to lead/acid battery manufacturers and looking at their suggested operating conditions, it would seem that their definition of "standby use" is basically what we have in a typical vehicle with an electrical system in good condition ................. and most of these guys recommend keeping a fully charged battery at around 13.7V (just below a typical point where lots of gas starts forming during charging) when in "standby use" - I guess Bosch may have been using the same logic in our regulator designs, and given my vehicle's own electrical performance and the absence of "dimming" lights syndrome when other loads are switched I must say ito of simplicity its probably more than adequate.
While I agree that "load voltage sensing" is probably the ultimate when looking after the performance of the load and its requirements, I feel that its probably not the correct thing to do on a typical vehicle with funky earths/connections etc etc etc. The problem imo is defining what the "load" to be sensed is going to be - if you choose the battery (that I would suggest) you still have to assume that the wiring on the vehicle is in 100% condition with no bad connections anywhere in order to really benefit from the extra complexity. Any bad connection or too small a wire gauge on any of the small vehicle loads feeding off the battery, will bring you right back to the OP's situation.
I still think my earlier recipe will be able to identify the real culprits once the OP comes back with actual initial measurements - irrespective of reg setup used
As for your temp of the alt touch test - I must be a sissy - if my engine is at normal op temp, there is no way I am going to be feeling-up my alt for anything more than probably only part of a second.
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