Battery problems, please help.

I have a 1994 3000GT SL with about 90,000 miles. The battery went dead on me 2 days ago, the problem is that the battery is only 45 days old. I brought the battery back to where I got it, they ran a test and said the bettery is fine (still holds charges I suppose?).

I tried my multimeter on it, the battery has a constant 14V output, like it reads on the voltage meter inside of the car, when I turn the ignition to ON position everything is fine, voltage on the dashboard reads 13 or 14 v, but when I try to start the car, all I hear is a click then everything shuts off for a second and all the indicator is dimmed. then the voltage meter on the dashboard slowly go back to 13V from 8V (takes about 30 seconds).

I have jump started a few times since then, everytime I jump start I'd drive for a while, if I don't have anywhere to go I'd leave it idle for to make the total running time for about an hour, but each time I shut off the engine, I can't turn it back on again. It seems like the battery is not getting charged at all, or the car is not charging the battery.

Right now I have the battery on a AC charger, if after several hours the battery is able to start the car, I suspect the alternator has gone bad. Any correction or better ideas?

btw: the positive terminal has corroded, it's got those green powders oxidation stuffs on it.

I checked the AC battery charger it indicates the battery is full/won't charge anymore, but when I turn on the ignition the windshield wiper won't even go half way before it stops, what does that mean? dead battery?

it sounds like its the alternator, I had the same problem whenI first got mine.

I would grab the battery out of whatever you are jump starting your car with. See if that battery will start your car. That will tell you for sure if its your battery or something else. The fact that you can jumpstart your car and it runs until you shut it off makes me think its the battery.

yea try to jump start the car, if the car works then take out the battery when it on (nothing will bad happen) then if the cars is still running then it not the alternator for sure, it could be something else.

i would say check the alternator... my boyfriends 95 3000GT SL drove for 30 miles before it died and the belt slipped off of the pulley that was for the alternator idk this seems to happen to 3000s.

Sounds like the "click no start" issue. One way to beat it is to just wire a button for a push button start, and that wil by pass the factory wiring, or try this link...

http://www.team3s.com/~egross/3S/Mods/All/StartFix/index.html

Mike

Everytime I jump start, I'd have to leave it idle for about 5 minutes before I can start driving or the engin will stall and I'll have to jump start again. That kinda lead me to think if I disconnect the battery while the the car is idle after a jump start it'll just stall... but I'll try it anyway.

So this is my theory, my alternator either died or just not putting out enough current to charge te battery and I ran down my last battery, I got a new battery but it wasn't being recharged so 45 days later this battery is out of juice too. I'll probably have to buy a reman alternator to find out, I think there's some trouble-shooting steps in the factory service manual that involves a multimeter but urgh... it wasn't long ago I replaced the IAC now this, I am still waiting for a driver side window regulator motor to come around on ebay (that's not a rip-off), y'know there's many toll booth on FL highways... no state income tax my butt, they sure make it back on the tolls.

hum.. this is going to sound really weird.

This afternoon I didn't even bother trying starting the car without aid, I connected the emergency jump-start portalble battery thing (what I've been using for the past few days) to the car and started it. But after I reached the destination about 30 minutes later, I shut off the engine and for no reason I decided to try again, well this time the engin starts. I scratch my head... then I turned off the engin, turned on the head light, high beam, fog light, wipers, stereo, A/C and I tried to start the car again, it started with no sign of hesitation... that's bothersom... but for now, I can only scratch my head.

and I'll look into the clicking problem URL for sure.

well, if the battery is toast, after driving your alt might have stuffed enough of a residual charge in it for it to start again, right after shutdown. wait about 30 mins or more and see if it will still start. after the rest of the stuff you have posted here it may not be my solution. but hey, its a thought.

I do have the click start issue... My solutioon after being stranded one to many times at 0300 in the morning was to install a push button from batt to starter. it completely cuts out the key and everything, but I do still have to have the key inand on run in order for the car to start, but I can crank the motor via the switch at any time. and right after I did this is when some one posted the link that I sent you to cure my issue.... Hind sight is 20/20 right?