Excellegions

I have a 87 trans am. I cant jump it cause once I hook it up to he other car the positive side instantly sparks like im toching a negative to a positive, and if i leave it on the jumper cables melt. when I disconnected and took out the battery from the trans am it charges normaly, but if i put the jumpers on the terminals of the car, it sparks. I tried to hook up only the positive terminal to the other car and ground the neg cable to the car body, as sook as the neg cable touched the body of the car, the posiitive would start to burn and melt. any ideas what's going on in the car?

camaronewbie

You connecting one side wrong somewhere.

Battery in the car - Pos battery cable runs to starter, neg batt cable runs to engine block - is that how you have the battery installed in the car?

Excellegions

yup, i triple checked that all is hooked up the way its suppose to be, the car was fine before, I use to be able to jump it and sart it fine, the only differnce this time was tha the harness of the alternator was old so it practically turned to dust in my hand,so i put a one wire alternator in it. while driving all of a sudden the car shut off, complete lost of power, that's when we tried to jump it, and this poblem started happening.

camaronewbie

I'd go back and verify the new alternator & wiring then.

Excellegions

the alternator just has one wire that you connect to the battery, and it constantly charges it. It was working fine when it was installed and we drove the car for a good 70 miles before the car just shut off. And while the car was driving the carge was above 13v so the alternator was working more than ok. It's like something else happend instantly for the car to shut off and completely loose power, and make the terminals act like this now.

Jupiter

iTrader: (1)

It is sparking because there is a short somewhere.
I would start with checking the alternator.

P.S. unplug the alternator and then try to jump it.
If it still sparks when connecting the jumper cables
then the SHORT is not the alternator.

EDIT: heh, an active circuit with the key off will
do the same.

Excellegions

I just tried that, i disconnected the alternator and it still sparks, The only thing now I guess is to trace the wire that is going to the starter. i see two wires going to the positive terminal. I know the big one is the starter wire, what is the other smaller one, do you know? I know that at the starter there are two smaller wires that I believe go to the computer.

dirtywhiteZ28

What did you do with the wires that were originally Plugged into the alt. at the white plug. Could that brown wire be in contact with metal somewhere?

mrrman

flagged to keeps tabs on this

Bronk

more info needed ...BIG SPARKS MEAN BIG DRAW. something is shorted. you are saying you always have to boost it to start it. Have you tried a known good battery.
A shorted out/open cell will cause a big draw and eat up altenators like crazy.

Has the battery been tested?