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Electrical problems

colbystephens

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Why would my battery cables get hot enough to melt off the ground terminal of the battery?

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I've had that happen on a diesel before... They draw a lot of current to begin with and I was cranking it to bleed the fuel filter. Switch it all over to the top post mount with 2 gauge or bigger cables and you won't see that problem again.
 
I had this problem before.
Does you engine start great when its cold?
And is very hard to start when warm?

I had my engine (high compression 350) timed by ear to run good. What I didnt know was my centrifugal advance springs were rusted off. I had WAY too much initial advance and I was busting off starter nose cones, melting wires off, burning up batteries. I was always needing a boost too.

I never thought about the advance springs. A friend brought over a timing light, we couldn't find the mark with it. I borrowed a fancy timing light with the dial back to zero knob. It was 32 degrees advanced.:haha:
 
This can also be caused by a poor ground connection to the block. It is very common to get some cancer in the cable causing a weak ground, this in turn leads to large amounts of heat in the cable. Look for corrosion on both ends of the cable, as well as a solid metal ground to the block. I prefer the ground directly to a block, as opposed to going to an accessory bracket, just because the ground path is shorter from the starter to the battery.
 
I've had a bad starter solenoid get my cables hot enough to make them soft, but not enough to melt the terminal off the battery lol.

Big engine, weak stock starter, small battery cables=hot cables.
 
Thanks for the replies. It ocurred to me after I had my wife post this, while I sat on the side of the freeway waiting for a topw truck, that I had probably shorted a hot wire to the frame.

That's definitely what happened. I had my truck towed to work, and fixed it later that nite. Claire drove behind me, saw sparks fly like crazy, and down goes the second battery. Apparently I didn't fix the problem.

Got it towed home. Gonna spend some major time finding the short and fixing it right!
 
If that is the case, and she was seeing sparks, I would be looking at the back of the alternator, as well as the wires running to the starter first. Alternator is less likely because of it's position in the engine bay, but a starter wire is definitely suspect.
 

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