why me???

I got a 90 mustang, well the battery keep going dead. I took out the lght bulbs for the the mirrors, they where staying on, well that did not work. I know it's not my battery it new, My husband is working on my car to turn it up. Could it beit has not been driven in 3 wks? or something eles?

Could be your alt is not putting out a good charge to the battery when you do drive it, then sitting for 3 weeks without starting is killing the already weak battery.

If the battery has been strong and the alt. is charging good, then you have a drain somewhere. Check for any other lights staying on. Other than that you can take a volt meter and hook in from the battery to the alt. and start pulling fuses one by one and watch for a large voltage drop. Look up that fuse and fix the problem. If its a fuse that runs multiple things then unplug them one at a time with the fuse replaced and watch for a voltage drop again. That should be the culprit. You must have a good battery for this test though.

i'd get a mechanic friend to test the starting and charging systems with a VAT-40. that'll tell you if your battery and starter are actually good and don't need replacing. or let the car sit with an ammeter in the main ciruit and see if it's drawing with the key off. or both. that's a good start.

why test the starter you might ask? hell, why not?

and if you just try to test the volts across the battery, it won't tell you anything but the battery's static voltage, not accounting for any drain. come to think of it, charge the battery completely and do the static test, that's another good battery check.

Most of these problems on 87-93 Stangs point to the already strained stock alternator. And the rest ends up like HiFlow said, I would pull it out real quick and have it tested Autozone, it's something they do it for free.

Better yet, get the car started. Once its running, dissconnect the negitive side of the battery. If the car dies, its your alternator.

Better yet, get the car started. Once its running, dissconnect the negitive side of the battery. If the car dies, its your alternator.

Yup. It's old school but it gets the job done.

Did you just call me old school? Damn you just made me feel old, and I'm really not that old.

stang racer20 you just insulted a moderator! Highflow is gonna ban you!

lol

Did you just call me old school? Damn you just made me feel old, and I'm really not that old.

Hey your not that much older than me so dont feel so bad, lol. :thumbsup:

Did you just call me old school? Damn you just made me feel old, and I'm really not that old.

Oh so many comments so lil time!