LeonBlackMax

Ok i put a system in my car. A JBL 1200 and 2 audiobahn alum12x. Well rite away my alternatory went out. So i got another put in b/c i just figured it was already bad or something, WEll i got thenew one in and it did the same thing. So i brought back my car and they said it may have been defective so i got another one free of charga nd stuff. Well it started again. So i took everything out of my car and put a very small amp on one of the subs. It still dimmed the lights a lot and started whining. Now i have nothing but the stock head unit and speaker hooked up. WEll i look at my receipt and its says . Nissan ALTIMA instead of a Maxima. Now did this fool put a altima alternator in my maxima. If he did i've went through lots of trouble b/c i looked at autozone.com and it says the 97 altimas have a 80 amp alt. and the max has either a 110 or a 125.
Now How can i look and see if i have the altima or the maxima one?

Soon2BMaxed

your best bet would be to go up there and get an alternator that you KNOW is for a Max and compare them next to each other.

darrick

autozone will give you anything

99MaxOnDubsSE

if you're buying a new alternator, you might as well upgrade to a high output one. it could be the system being too strong. maybe....

Ben

nadir_s

What you need is a capacitor to compensate for the peak levels in sound and it shoudl solve your dimming problem. Upgrade ure battery if you can as well. Good luck on your alternator

jmax

Yes, the cap is what you need. But don't get a bargain variety cap. They just don't seem to have the 'juice'. A new battery will only help if the old battery is bad. Beleive it or not a battery is a strain on the alternator. Because it is always discharging, the alternator has to keep rechargeing the batt. In my car right now I have the stock battery powering 3 class AB amps for around 1200 RMS watts. They have a total of 200 amps fusing for near max power. No dimming at all because I have heavy wiring and a good cap.

kingrukus

iTrader: (41)

It might be something else that is causing this problem. I have a JBL BP1200.1 running off of a 90 amp alternator, and my lights do dim, but not that much. You may also want to change all your wiring to 0/1 awg.

ivelweyz

You're supposed to have a .5 farad capacitor for every 1000 watts you have in your system, it's safer , much much safer that way...

LeonBlackMax

All of what you are saying sounds good , but i didnt get the alternator from autozone. i got it from a local mechanic, i also put a very small amp , like 300 watts on it and it dimmed teh hell out of the lights. when my windows go up and down, my lights dim. I dont think a cap can do much for me. Anyway once the cap is drained, the cap is getting juice fromt the battery which needs its juice from teh alt. So its just more and more strain on it. I also but a huge *** battery my dad had. It lasted a few minutes and once it went low on juice it acted like a small battery b/c my alternator doesnt charge it right.
i'm hoping that i just got a altima one put in , but just incase i'm gointo tell him to upgrade all my wiring for me under my hood and i'm going to buy an optima battery.

jmax

Well, the wiring should have been upgraded before you installed any amp. Much less a 1200 watt JBL amp. But now you are changing your story and saying that you don't have a huge amp. You caould put in a 10 kiloamp alt in. But if the wiring is cheap, poorly grounded, too thin, etc. the lights will still dim. The general rule is 1 farad per kilowatt. And always round up. So more than a kilowatt means more than one farad. And the bigger the battery the bigger the strain on the alt. Caps strain on the alt is limited primarily to the moment the stereo is turned on and the cap is charged.

LeonBlackMax

i'm talking about the wiring under my hood , not for the amp. i have 4 gauge steetwires and nice fuses and fuse holders and good grounds and all. And i havent changed no story. First alt i had the JBL and its killed it. Second alt i had a profile amp ont and it died. i'm now on my third. its makin noise too.

jmax

The factory ground from the engine block to the chassis is a very small 4 gauge, more like 5 or 6 gauge. That needs to be replaced with 4 gauge minimum, heavier would be better. Then you need to replace the factory battery to ground. And 4 gauge for the length of cable needed to get from the battery to the trunk is only good for a max of 85 amps current. If you go that high voltage will start to drop as you are seeing in the headlights dimming. As voltage drops, amperage goes up to compensate, ohms law. So if the system is drawing 150 amps at 12.5 volts, that's 1875 watts to power the amp, when voltage drops to 12 volts amperage goes up to 156 amps. If voltage drops to 11.5 volts, amperage will go up to 163 amps. And so on. I used 150 amps because that is what my MTX 1000D, 1000 watt amp is rated at pulling near max power. Since JBL sells their amp saying that it puts out 1200 watts, the current demands should be increased.
You need 0 gauge or better to power that one amp. Here again a cap would help because the voltage supply is aided by the proximity of the cap to the amp.
A good ground is to the chassis, not the body. Check it. And make sure the negative wiring from chassis to amp terminals is at least 4 gauge. You should also check your alternator wiring and belts. There should be two positive wires going to the regulator. If they are using the factory harness it would be difficult to confuse them. One is always on, the other is switched on when voltage drops. This is essentially the on/off switch for the alt. If the belt is not aligned correctly it could ruin the bearings and burn out the alt. If it is too loose, the battery won't be able to charge and the alt can burn out. If the idler pulley itself is tightened too much, the alt might not turn and the belt would likely burn up. If the idler pulley is cranked down too far, that could burn out the alt pulley.