Battery terminals are hot!!! Almost burned my truck down

[AustinDube]

So i almost burned my truck down, my battery cables are corroded and old, hoping if I throw in new wires this will not happen. Its a tight clean connection on the frame n starter but when I went to start it the wire melted and started smoking from the positive wire on the back of the starter. Anything else to change due to that?

 

[1987 GMC Jimmy]

Sounds like a dead short to ground. You're replacing the cables, and you've verified the frame ground is clean and tight, which is good. Since you're doing all this, make sure the ground strap bridging the passenger side cylinder head to the firewall is clean and tight, as well.

 

[bedwards]

Are you sure the starter has not gone bad? Don't ask me how I know =]

 

[HotRodPC]

bedwards has a point. If the starter has gone bad and has excessive amperage draw, that will certainly cause your cables to get hot while cranking.

 

[1987 GMC Jimmy]

Hmm, maybe it'd be a good idea to test the voltage drop across the battery to see if the starter's pulling too much. If he hasn't changed the cables, then the voltage drop could be tested across the positive side, too.

 

[AustinDube]

Yes its a new battery and starter, and also i will need to clean that ground on the firewall but mine goes to my cyl 8 manifold bolt is it supposed to be there?

 

[1987 GMC Jimmy]

Yes its a new battery and starter, and also i will need to clean that ground on the firewall but mine goes to my cyl 8 manifold bolt is it supposed to be there?

It came bolted to one of the holes on the rear face of the cylinder head. I don't see it being an ineffective ground having been bolted there, but I don't know why it would be unless the threads were filthy or damaged on the back of the head.

 

[HotRodPC]

Very common to see the ground battery terminal bolted the Alternator bracket too. Checking the ground strap from the engine to the firewall or chassis might need to be checked out too.

When you say starter is new, do you mean it's a new remanufactured or new? Remanufactured from a discount auto parts store usually don't mean jack. It just means it was cleaned and replaced what it needed and some new bearings in most cases.
I'd still do the starter draw test on it. Either by amp guage or volt guage. If it's not in good shape, you'll have quite a drastic voltage or amperage drop while cranking the engine. It is normal to dip some but if it's excessive, it can certainly cause the problem you're speaking of.

 

[AustinDube]

Yes it is a pile remanufacured one and its the oem full sized style, and would a mini high torque starter be better or? and I also found out that my chassis to motor ground is half torn so i'll replace that

 

[1987 GMC Jimmy]

The high torque starter is lighter (especially helpful with R&R), more powerful and can turn the motor over faster, but the bulky dinosaur starters are very adequate when they're in working order. I just had a big Delco unit rebuilt, and I'm very happy with it. I'd get the old one rebuilt by a reputable guy if it's a Delco, and I'd highly consider the high torque if your motor is greater than or equal to 10:1 compression, or you plan on building it up it to that later. Aside from those parameters, just get the one that you like.