Alright - after i replaced my tranny with a T-5 (and left my interior lights on for 2-3 days, my battery died. So - i recharged the battery, finish the swap, and go driving - but my charge is down to around 8 volts and today it fell to 0 volts. I pulled the alternator and replaced it with a spare v6 one i had lying around (1987 coupe it came out of) and my charge was back up to 15 volts or so. Well, after a short drive it was back down to 7volts of charge and i'm pretty sure the alternator is dying again (the car seems to have a skip too when the alternator is going - like a hesitation). My question is this - what could kill two alternators? I've looked for a short near the hot wire to the starter: nothing. I'm just plumb confused. Any help ANYONE?

Tyler

 

It is pretty hard to cook an alt. in such a short time. Unless you short the output wire chances are something else is going on. If the battery discharged like you say it is possible to develop a sulfation between a couple of plates. This could cause the alt to shut down charging. You MUST start with a known good fully charged battery before you start to troubleshoot. If in doubt get it tested before you go on. You said you changed the trans? Is it possible you pulled off a wire from the starter junction? That is a tie point for feeding some circuits in the car. My opinion is that something happened internally to the battery. The alternators are protected from shorts by a fuse link to the battery, from excessive charging by a temp control as well as overvoltage protection. Check these things and follow up here. As always inspect all cables, and there are some reports of the ground braid from the block to the chassis causing intermittent or no charge conditions. If you have a voltmeter, when it's running measure the heavy wire at the rear of the alt, then measure across the battery terminals. They should be the same, if not suspect an open circuit between the two.