93 alternator 3rd new one

[jdk]

ok guys whats going on? i got the truck back in october, put a new alt on it, it was still on warrenty. last week comming home from work, the battery light came on. i had it tested today and it was bad. got another new one on warrenty. when the previous owner had it the alt (orignal) caught on fire and it hasn't been right since. whats going on guys? why do i keep blowing up alts? both plugs on the alt were replaced by the previous own btw. thanks guys

 

[blacksnapon]

Bad battery, poor battery cables, poor connections (grounds), even bad alternators. More diagnostics are required, voltage drops, parasitic loads, short circuits, cobbled wiring, etc.

 

[rickpilgrim]

Our 87 F250 4x4 w/460 killed 2 alternators and when exchanging #2 the parts guy asked if we had replaced the plug in as in this generation of trucks the plug goes bad and causes high resistance which overloads the alt and kills it. Make sure the battery and bat connections are good first though. We replaced the plug 16 months ago and no more problems.