1991 GMC Truck Smoking battery-no power anywhere to car

LABKAY06

MEMBER
1991 GMC TRUCK
V8
4WD
AUTOMATIC
174,000 MILES

I recently diagnosed a bad alternator in my 91 GMC 1/2 Ton pickup. I bought a used alternator (100 AMP) from a local salvage parts store. I put the new alternator in my truck and when I hooked the battery cables back up to the battery I got a big spark and no power anywhere. I hooked my wifes car up to jumper cables and after about ten to fifteen seconds the batter started to smoke on my truck.

Monday, October 26th, 2009 AT 8:57 PM

3 Replies

RASMATAZ

MECHANIC
75,992 POSTS

You have a direct short to ground you sure the battery polarity is correct.

Was this thing happening with the old alternator?

Was this

answer

helpful?

Yes

No

Monday, October 26th, 2009 AT 9:46 PM

LABKAY06

MEMBER
2 POSTS

I didn't have any sort of problem like this with the old alternator. Do you know which cables go where? Positive/Negative. Thanks for your response.

Was this

answer

helpful?

Yes

No

Monday, October 26th, 2009 AT 11:09 PM

RASMATAZ

MECHANIC
75,992 POSTS

At the battery the plain black cable goes to the negative post of the battery and the small red and black to the positive battery post to include another black battery cable goes to the starter battery terminal- If it continues disconnect the battery cable at the starter isolate the cable from ground then hook up the battery and see what happens

Was this

answer

helpful?

Yes

No

Monday, October 26th, 2009 AT 11:50 PM