Alternator/electrical problem
 

Any help of redirection to old post would be appreciated.
1981 Toyota pickup I thought my alternator was going bad due to battery not charging(new battery) changed the alternator and was checking voltage everything seemed fine but after running for about 45 seconds-1 minute the black wire from the alternator plug began to smoke, so i disconnected battery and shut off the truck. I was assuming the wire was shorting out some where but have traced it back to the firewall and not found anything yet. I did notice this only happens when the voltage regulator is plugged in, could this perhaps be bad and is there any way of testing it without it running? Thanks

:wrench: Is the new alternator bad ??

What kind of voltage did you have with the old alternator??

I take it you don`t have the EWD for your truck I don`t have anything that old

Having the schematics would tell me how to test the regulator. .

The 84 and older trucks have an external voltage regulator. I forget where it is mounted but I think it is a black metal box if I remember right. Wonder if it the part failing.

It does have an external voltage regulator. I replaced it about a year ago. I opened it up and compared it to the old one and it looks fine. The old one had a burnt out wire on one of the coils. If the new one were bad I would assume it would look similar to that one? In regards to the old alternator I didn't check it but looking back I don't think that was the problem. I believe something is shorting out some where