Negative Cable Grounding Problem

[67Satty]

I switched from iron heads to aluminum heads. I hooked everything back up exactly the way it was before: negative battery cable attached to front of driver's side head, braided ground strap going from back of passenger side head to firewall. Trying to crank it over ended up smoking the 12 gauge wire that's crimped to the negative battery cable pigtail that goes to the inner fender.

So the only thing that changed it switching from iron to aluminum heads. Could that have caused the grounding problem? Or something else like bad connection between the cable terminal and the negative post of the battery? Or maybe the crimp connection between the negative cable pigtail and the 12 gauge wire going to my inner fender was crappy? Any ideas? Thanks!

 

[451Mopar]

Sounds like the large battery cable to block did not have a good connection either at the head/block or maybe the battery terminal end, so all the current went from the braded cable to body ground, and body ground through the small battery connection wire.

 

[khryslerkid]

Apparently the ground wire from the battery isn't grounding enough. Current follows the path of least resistance. Head gasket and sealer not allowing a good ground. Sealer on the bolt insulating the cable? Try cleaning the bolt from sealer and or oil and the bolt hole.

Are you using a manifold bolt or the bolt hole in the head? Maybe try a water pump bolt?

 

[67Satty]

Sounds like the large battery cable to block did not have a good connection either at the head/block or maybe the battery terminal end, so all the current went from the braded cable to body ground, and body ground through the small battery connection wire.

Thanks, that makes sense because the little pigtail coming off the negative battery cable was fine but the wire between negative battery cable pigtail/crimp connector and the fender was fried.

I bought a new negative battery cable because the old one's terminal looked ovaled-out and deformed.

Stupid question: do I want the cable that bolts to the aluminum head to bolt directly to the head or do I want some kind of washer somewhere? If I use a star washer do I want it between the cable end and the head or between the bolt and the cable end?

 

[67Satty]

Are you using a manifold bolt or the bolt hole in the head? Maybe try a water pump bolt?

Bolt hole in head.

 

[khryslerkid]

The hole in the head would be my choice also.

I know you bought a new cable but don't rule out that it could be bad. I've heard several say that they had new cables that were defective.

 

[Cranky]

I always put the star washer between the grounding surface and the cable eye.

 

[Fran Blacker]

You might want a star washer between head and cable.
https://www.google.com/search?sourc...yzlkKHVjfD9kQ4dUDCAs&uact=5#spf=1572548576975

 

[67Satty]

The hole in the head would be my choice also.

I know you bought a new cable but don't rule out that it could be bad. I've heard several say that they had new cables that were defective.

Sorry, what I meant was a bought I new negative cable after smoking the wire going from it to the inner fender and noticing that the negative battery cable terminal was ovaled-out and maybe not making the best contact with the battery post.

 

[451Mopar]

Not sure why the connection may have been bad? I still think it had to be at the ground cable connection or inside the cable.
I would think the heads should be grounded to the block through the Head gasket fire ring, and head bolts? And the block grounds the transmission housing that the starter is connected to?
It is fine to add additional grounds if you think there is a bad connection between the starter and battery, or any electrical part and the battery.

 

[Lefty71]

Sounds dang unlikely... but did you check for continuity between the heads, and between the heads and block?? You couldnt have used that much permatex lol. And I would think the head gaskets themselves would carry the current flow with the sealing rings, not prevent it.

 

[cryplydog]

I ground to the block and then to the frame, plus a floppy ss cable from each head to the firewall. Never had any ign. or plug troubles works great and don't miss a lick. cain't hurt