87 runner kills alternators

Four alts in 5 years and I'm sick of replacing them. The one in there now is hanging on by a thread. I've disabled all unnecessary power suckers (turn signals, radio, horn) just to keep it going til I figure out the problem. Has anyone out there run into this problem? Put a new engine in 3 months ago and the problems kept coming. Is it my electrical? ignition? Took it to a mechanic and he's stumped too! PLEASE HELP! I'm desperate. :banghead:

Maybe a bad ground somewhere? Like on the alt to engine block?

Thanks for the reply. My mechanic has gone through most of the wiring and fixed the bad grounds he's found. I guess I won't know if it worked unless I don't need another alternator in a few months : ) Do you think it could have anything to do with the ignition? I've heard that heavy key rings can pop something out of place.