Car will not turn over, battery completely dead, after changing alternator belt.

[sweetp01569]

I am hoping someone can help me. I replaced alternator belt, but when I was loosening the upper 18 mm bolt, my wrench touched the positive lead on the alternator and sparked (I should have disconnected the battery. I didn't think much of it, replaced the belt, tightened everything back up. Car started right up, belt looks good. I take an hour-long ride, park the car at friend's house. After about an hour long visit, I try to start the car but battery seems completely dead-nothing turns on when turning the key. Connected jumpers to friend's car to try to jump the battery, and the dash lights come on, but nothing turns or cranks.

When I sparked the wrench against the red lead on the alternator, what could I have damaged to cause this issue? Did I hurt the alternator or starter, or blew a relay/fuse? What's confusing is that the car started fine twice after replacing the belt, but I'm guessing I shorted something to prevent the alternator from charging the battery (which I guess just drained on the hour-long ride??). I left the car at my friends house, and now I need to figure out what is happening. Any help or guidance will be greatly appreciated. I will go over there tomorrow to investigate. Thanks so much!!!

[Bitsyncmaster]

You need to see if the battery will accept a charge. If not disconnect the alternator wires and then see if it charges. If so you alternator probably has a shorted diode.

[sweetp01569]

You need to see if the battery will accept a charge. If not disconnect the alternator wires and then see if it charges. If so you alternator probably has a shorted diode.

Thanks, Dave. I will test tomorrow. If diode is shorted in alternator, does that mean a new alternator?

[Bitsyncmaster]

Thanks, Dave. I will test tomorrow. If diode is shorted in alternator, does that mean a new alternator?

Yes a new alternator. Replacing the diodes is not something owners would do even if you can get the parts.

[David T]

Yes a new alternator. Replacing the diodes is not something owners would do even if you can get the parts.

Most auto stores will test your battery and alternator for free. If the battery is near (or over) 7 years old just replace it. Less than 7 years old, try to charge it and load-test it. As Bitsyncmaster said, you probably blew the diodes in the alternator and/or the voltage regulator. If you have the original Ducieler alternator it's time to dump it and get a GM alternator anyway. Alternators can be rebuilt but don't rebuild an old Ducey. The vendors can hook you up with a kit to replace the alternator. It is a bolt-in kind of thing with a minimum amount of wiring, easy to do.