DGruber 58

So I go to unlock the doors w/keypad (because the door lock's keys don't work)...nothing, not even a beep. After I broke in, not even the security light on the dash was flashing/beeping. So I try to jump it. Nothing. I am pretty sure we had the cables hooked up properly, the negative to the engine, pos to battery. I thought maybe I had a bad ground, so I directly connected to my battery, but still nothing. We didn't try connecting directly to his negative as well, because he had to leave. I checked a couple connections near the battery, tried pullling the neg off and put it back on (as sort of a re-set). I followed the positive to the starter, wiggling connections i could reach. When the tow truck arrived, he connected his jumper straight to the battery, and the alarm went off. Turned the alarm off and started the car no problem. Waited about a minute, turned the car off to see if it would start. Almost turned over, but didn't start. Jumped again and drove it home.
I could start it once I got home. That was about 15 min. ago.

Any idea what could have shorted? Nothing was left on, but even if it was, it wouldn't totally kill the battery. Any ideas? Thanks

«§»Craig B«§»

iTrader: (5)

battery could just be old and dead

take it to autozone and they'll test battery and alternator for free

I think the first time you tried to jump it, maybe you didn't let it charge for long enough

James92SE

iTrader: (31)

Yeah you didnt let it charge long enough the first time you jumped it. Turning it off and trying to start it after just a minute isnt long enough for the alternator to charge the battery. That's why you were able to start it once you got home, because on the drive home it had enough time to charge

How come when you tried to jump it yourself you didnt just go positive battery terminal to positive battery terminal, and negative to negative?

DGruber 58

i doubt its just a bad battery, as it sat for the past two weeks in temps in the teens and started right up yesterday.
When we tried to jump it the first time, the light on the dash didn't light and it didn't turn over. I have a charger at my dad's house that has an alternator test function... not sure how reliable it is (no autozone near me)

James:
http://www.popularmechanics.com/auto...t/1272356.html
Safety reasons. It wouldn't have hurt to try though

«§»Craig B«§»

iTrader: (5)

I think advance auto does the free testing too.

Like James and I mentioned, I think you just didn't let it charge long enough the first time you tried to jump it so that why it wouldnt' turn over.

May be a bad battery or something is/was draining it or whatever.
With the car off, put a voltmeter across the battery and you should have 12.8 or so. With the car running, you should have 13.8-14.4 or something like that. If it goes up to something in that range, your alternator probably is working.

DGruber 58

well i just tried to start it again, and again nothing, not even a light or beep. Something is shorting out. At least my alternator should be good, as I couldn't make it home just on my battery...

90MAXGMG

Its prolly the alternator...This is exactly what happened to me a couple of weeks ago...I was stranded at school and everything. First i went and got a free battery (under warranty) then when that went dead I changed the alternator. And now all is well

Cliff Clavin

iTrader: (11)

You can have your car tested for free at any number of places: Autozone, NAPA, Pep Boys. Almost any battery place (Battery Exchange, StartMart) will test it, too. You have a phone and a phone book, right? Just call the auto places near you and ask who will test it for free.

It sounds like it could be your alternator or battery. You should also check out your connections really good. Once a friend of mine kept having trouble with his car. He was too lazy to get it tested, so I looked and the battery terminal connections were corroded between the post and the connector. It looked OK from a few feet, but once I took the cable off (it was nasty underneath) and cleaned it, the thing fired right up after being jumped the first time.

greggie195

iTrader: (1)

Just a word on the battery tests. I had a battery tested at Aid Auto that I thought was bad. Well the green dummy light was dead (so at least one cell was bad) but the tester said it was fine. I took it to my mechanic (this was my 200sx) because I just got a new alternator. He said the battery was bad and that you cant always trust the testers. He put in a new battery for free (still uner warranty) and thats was the end of that problem!

michaels'max

this may be a stupid question, but when jumping a car, is the time in which it takes to jump the car dependent in anyway on the person who is jumping's engine or any other part of the car, or is it completly dependent on the battery itself that is being used. I only ask because I tend to see a correlation between the size of the engine on the vehicle which is being jumped and the time it takes to jump my car. I understand that perhaps it takes a bigger and/or perhaps a more powerful battery to operate a larger engine or car. maybe that is the answer? or is it just coincidence? my friends were trying to jump me one time with their little four cylinder hatchback chevy nova. We stood there for over 20 minutes trying to jump it and charge my battery, the lights wouldn't even turn on. Then someone with a v6 mercury cougar helped out and once we connected the cables the light's turned on in my car and we jumped it almost instantly. And yes, the cables were connected correctly both times.

please be gentle I'm not a morron, I just am not electically savy.

aminus21

iTrader: (14)

I dont know if it's "safe" but one way to test the alternator wihtout removing it, is to disconnect the battery cables while the car is on. If the car dies the, alternator may be bad..

michaels'max

Actually I've tried the whole disconnecting the battery cables while the car is on thing. For my vehicle it doesn't mean anything. I don't know if it's just the wiring or what. I do know that, that is a test that can be performed on most cars as I have seen it done before however with my 92 nissan maxima gxe with auto trans. taking the battery cables off while the car is running will just kill the car whether the alternator is dead or not. I don't know why it just does. I tried it after I replaced my alternator and it would not stay running unless the batter cables were connected. The best I can assume is that having them disconnected is like breaking a circuit to where the electricity can't cycle properly. I don't know, if anyone can answer why this works on some cars and not others, that would be appreciated.

Wiking

Taking batt off from running engine is russian roulette: will kill ECU, TCU etc myriad computer onboard - one day. If u like u car, never do that.

Verifying alternator is done only by checking the already mentioned voltage at batt: min13.8V

James:
Jumping: negative jump cable should be always on engine. ALWAYS. On both ends, recipienct & donor cars. If donor wants to save alternator from zap, that is. Please read any pro manual about that... This way there is always few ohms resistance [cable connector connectionc] which shields donor voltage requlators from burning, recipient battery from too high sudden current spikes.
Btw. The tow car guy should go back to the farm... never let him do that again!

Battery basics:
Cold battery -10? has very low capacity to be charged, maybe 10% of what it is at say 50F. Depends on batt type, age. This charging thing drains pwr from donor. Its the Donor battery condition AND how thick jumper cables u have that define the current flow to receiver. Alternator has very little, vehicle size none effect. Also how good connectors, how well connected. All heating jumper parts mean loss in jumpstart pwr.

Battery has lost half of its output pwr at zero temp. In -40 its output pwr is juts 5%. Warm battery, and get 100% output like miracle; the power is there, just frozen in, cannot come out... Warm it any way u want: take home, bring hot pot beside... take stime though. Or keep small lamp overnight on; that warms batt internally.

It takes time to charge the dead batt to quarter capacity, warm internally: let the donor idle at 1500rpm for ten minutes if nostart at first try. There the donor alternator output capacity has real meaning [btw, stock bigger rigs tend to have bigger capacity alternators].


checkout:
http://www.cardomain.com/memberpage/748507/10
http://www.cardomain.com/memberpage/748507/14



.

DGruber 58

thanks for all the replies
I took the car to my Dad's and cleaned up the battery posts and ground, then I started checking voltage at the fuse box with the car off key out of ignition. The "Room Lamp" (overhead light) was drawing 12-13V, even in the off position. If I turned the light to the auto position, it would slowly drop to about .6V when the door was closed. Any ideas if this is normal (I doubt it), or any ideas how to fix it? Right now I just pulled that fuse out. The "Electron Batt" (no idea what this one is to) also was drawing 12-13V. It is the one highlighted in white on the fuse cover. Any ideas about this?

I left the neg cable disconnected over night to see if the battery was bad. In the morning it was putting out I think 13V even. Started up no problem. When I got to school I disconnected it again, just in case I haven't fixed the problem yet. I'm going to let it sit overnight all connected with the "Room Lamp" fuse out and see what happens tomorrow morning.

My alternator is good, as 1.the car made it home yesterday after just a jump (he took the cables off immediately) and 2. The battery measured 13-14V while running. I forget the exact amount, but it was more than just the battery.

So my questions are about the two fuses, or if you have any other places you know of that might short the battery completely in about 6 hours. I'll probably get a new battery anyhow, just to be sure.

Wiking

...what does this mean? "also was drawing 12-13V"

If u batt is low, cab lights may drown u batt. If batt ok, main lights do that in 4hrs.

Might be bad alternator, measure how much it draws AMPS by taking its fuse off and measurin over its pins (beside batt). Should not draw any as engine, all off. If smtg is seen, its the voltage reg blown (Farmer-jumpings?); replace alt.

DGruber 58

Wiking
I used a voltmeter and touched the pins where the fuse goes and measured 12.something volts. Do you know what the electron batt is/does?
I fully charged the battery when I went to my Dad's, before I measured anything.

Wiking

Yes, u now measure voltage, that is not what smtg "draws"... This info really does not help you.

For alternator, learn hor to measure current flow: the measured curren has to flow VIA your mulimeter, otherwise no use.

Here is one LAW that waere created, humans found out: Volts X Amps = Watts

Bedtime here, good night/day?

DGruber 58

My clymer manual suggested doing that to find shorts. Since the car is off and key isn't even in the ignition, there shouldn't be any measurable volts at the fuse box, right? I figured the "electron batt" might be an exception, since it is highlighted on the cover.

I'll have to read up for measuring the current flow.
thanks for the help

lalo

NO, even if the key is not in the ignition their will be volts in the fuse box, how do you think your door lights come ON and seatbelts retrack even if your key is not in your ignition? Have your alternator tested, even if you fully charge the batt, it might not be retaining the charge becuse its old/defective. Your alternator might be about to go out aswell, proly has enough power to run the car but not enough to charge the batt. hope this is clear.

Geerhed

iTrader: (1)

You got 12V at the interior light because it stays on for a few moments after the door shuts... then slowly dims down to nothing: just as your multimeter showed.

DGruber 58

lalo, Geerhead
when the device, such as the lights, are activated, then there should be voltage, but not constantly. Like the horn, when i touched the tips in the fuse box, no voltage. Press the horn, 13V. When the overhead light is in the "off" position, so that it doesn't even turn on when the door is opened, is when i measured 13V. In the auto position (middle), it measured 13, then faded to about .6V. When in the on position, it constantly measured 13V.

I still have to check my alt though. Sometime later this week when I get some time.
edit: and does anyone know about the "Electron Batt" circuit?

Geerhed

iTrader: (1)

I'd have to look at the schematic, but it's possible that the switch on the light just removes the ground from the circuit -- that the +12VDC is "always" there, but the switch merely closes the circuit to ground. Many circuits operate this way.

DGruber 58

Update
I let the car sit overnight and all day with the "Room Lamp" fuse out. I went out and just checked some voltages:
Battery with car off: 12.7... down a little
Batt with car on: 14.5...same
Electron Batt fuse block: 12-13V with door open or closed, no difference...same
Room Lamp: with light "on" : 12-13
with light "auto": .6-13, depending on if door was open or not
with light "off": 12-13
all the same

I'm going to put the room lamp fuse back in, probably tomorrow when I'm sure I have a charger, and see if it drains the battery.

Geerhed

iTrader: (1)

That's really odd about the 'room lamp' circuit.
Are we talking about the dome light? If you can, test the switch. Unplug (if they're not soldered on) the wires from the dome light switch. Now, test for continuity (0 Ohms) across the switch in the various positions.
Should show: OFF = Infinity Ohms, DOOR = 0 Ohms with the door open, and Infinity with it shut (after a few seconds), and ON = 0 Ohms all the time.
The fuse box will supply 12VDC to the switch at all times, regardless of whether the key is in or not. If it's running all the time, your switch is bad (or possibly one of your door switches is bad if it's running all the time and is in "DOOR" position.
Am I making any sense? Best of luck, and definitely let us know when you've solved the problem.

lalo

When the car is "ON" the Alternator is chargin the batt thats why batt was ok with the car on. Your batt is not retaining the charge, (its bad), thats why power goes down when car is off.

Either way, you should take it to a Local auto parts store, Like Greg said and have them test the batt out, its free and if thats not the problem for sure, then you can further diagnose the situation.

This is a long shot, but usualy with our cars we have problems with our shift linkage not engaging in park all the way. So when you turn the key nothing will happen. Starter/engine wont turn. So you have to tap the Shifter higher than "P" and the car will start. Its a safety thing the car has so that you cant start it in Drive or Reverse.

and now that you have the voltmeter out test the switch (forget the name) thats conected to your shifter, every time you hit the break (car off) you should hear a cliking sound on the shifter. "I think" if that is stuck/malfuctioning your car wont turn on. Just my opinion im no expert.

«§»Craig B«§»

iTrader: (5)

yeah, that's exactly how the dome lights works - switched ground

DGruber 58

craig
so there should always be 12-13V at the fuse block? Shouldn't it be the same, regardless of switch position then? After work today i'll check my switch.

DGruber 58

today i pulled the dome lamp off and after disconnecting it, still 12V at the fuse block. Looking at the switch, one wire from the electrical connector is directly connected to positive power source. The on position uses this wire and a direct to ground within the switch. The auto uses this power wire, and the other wire goes back through the electrical connecter somewhere (eventually grounding, because the switch does function properly). The off position uses this other wire, and just a blank spot on the switch, so no light, ever.

So I guess the overhead light wasn't the/a problem.

That fuse protects:
Interior and spot lamps, Time Control Unit, Key Switch, and Warning Chime
Any ideas?

Chris Gregg

iTrader: (59)

It's really hard to teach electronics 101 in a chat forum. Take it to someone so they can diagnose it for you! Why did one car charge your Max and the other not? Well, like said before it could have been a number of things. Alternators all put out about the same amount of volts (stock). I say that there were a number of contributing factors to this. 1. The cables were not secured good on either side (charger or chargee). Sometime just becuase they are touching does not mean there's a good enough connection, exactly why you TIGHTEN cables to post on battery. 2. Needed to charge longer. 3. The cables you were using to charge were the cheap 10guage "cables" and it contributed to #2. Advice: pay the money and get good, larger cables like 2-4 guage.
As far as the fuses you mentioned. The Elect Batt fuse runs all the ecu and sensors (like O2 sensor) for the engine. It will turn over, but will not fire if this fuse is removed or bad.
If the battery has a bad cell, it can leak down slowly over time. It looks like you've established the alternator is putting out what it needs, but that still does not rule out the battery. This is further a problem (as already mentioned) by temperature. Hope you figure it out. You know, you might also check and make sure all the doors are shutting right. Sometimes if one does not shut, barely tell, it will leave the door lights on and drain the battery, whether the upper light is on or off. Recommend checking door that it shuts tight everytime. The plastic coating on the car wears out and the latch will not fully catch. Hope this helps clarify some questions you've asked.

DGruber 58

Another Update
Last night I put the dome lamp fuse back in, just to see if the batt would drain, etc.
No problems, about 13V at the batt, starts right up. I guess a good cleaning of the posts and grounds fixed my problem. I'm still not sure what is using the 13V on that fuse, but it doesn't appear to drain the battery. Thanks for all the replies