87 IROC CAMARO 350TPI

ok i have stated before that my batt and alt are good, there is no draw that i have tested for and found (when car is off), and yet my batt drains when the car is on.
ive noticed that after a decent charging of my batt, the car can hold that charge when it is on although i have not had it on for long enough to see if it holds up forever. usually on hot days, i turn my car on and after a minut it will noticeably drain my batt. WHY COULD THIS BE HAPPENING? like i have stated before, in accessory mode my batt is at 12 volts and when i turn on the car it is at 10 volts????whats up with that?

 

I would suggest to clean your battery first. Take a voltmeter, put the positive lead on the positive post and poke and prod around the casing of the battery to see if you have some voltage. If you do have volts between the post and the casing then that's your drain. As for your lose of volts when your car is on, how do you know your alt is good? Did you load test it? The only thing I could suggest is the alt is bad or faulty.

 

my alt has been tested, im pretty sure it was load tested as the meter on the machine read around 14 volts.

well i bought a new batt and the same thing happened it just drained. it seems that when the car begins to get hot or warm up , the batt will then drain. i disconnected my fans thinking it was shorting out when the car got hot(because they currently dont turn on for some reason), but it drained anyways.

 

Have you turned your headlights on and noticed if they are dim? Then when you rev the engine do they get brighter? Maybe your gauge is just inaccurate. I doubt it, but a possibility. That is very weird indeed. My friends Ford Probe is doing that too. On hot days especially, the battery charge will fluxuate. I'm going to do some more thinking on your subject.

 

You checked all your connections, grounds, etc.? If you have a loose connection somewhere it may be getting knocked around when the engine is on, but not when it is just in acc.

 

all connections are tight and seem to be in good condition. when i turn on my lights after i have charged the batt, they are bright, only get dim when the batt begins to die. im thinking i should just get another alt and if the problem continues then what would/could it be? so i can know ahead of time

 

Oh this is just great! I just went out to my car and guess what... there's no juice. This is weird. I respond to your post about your problem and I some how contract it as well. Thanks man, you must be contagious or something. Well now I have my own charging demon to battle. Getting a new alt is a good try. As for what to try next if that doesn't fix it, I can't think of anything right now. Hopefully someone with more knowledge will respond to this post. If I think of anything I'll let you know.

 

haha contageous? i hope not, dont wanna spread this horror to other ppl.

any ideas on what could be wrong if i go out and by a new 140 amp alt and my car still drains when on?

 

Unless you have an ungodly amount of accessories running, it would really be pointless to just get a bigger alt in my opinion. The original alt supplies plenty of power to the battery. I suspect that either your alt is somehow faulty or something is prohibiting it from doing it's job.

 

load test alternator and also check condition of battery clean it up check all cables and check fusible link from battery to alternator. also check for belt slippage and check that the alternator spins freely and don't bind up and check to see if there is voltage at exciter plug on back of alt.