Bad battery ground

[c10boob]

Whenever I start my '71 C10, especially after the engine has warmed up, it has a lot of trouble. I either have to try multiple times, each time hearing a single click from the starter, or I have to wait for the engine to cool down or it may not start at all.

My negative battery cable (an older 2 gauge cable) is getting hot to point of melting, so there is a bad connection. This cable was connected to a bolt on the exhaust manifold. This seems like a bad spot due to transfer heat, so I was thinking of connecting it to the frame, but there seems to be a lot of different opinions on the internet about this.

I've found the same problem on an older post here: http://67-72chevytrucks.com/vboard/s...ad.php?t=90481

... but didn't know if the connection would be different for my truck since the above linked post is for a newer vehicle than mine, and I don't even see where the engine has a ground cable to the frame on my truck.

Any thoughts or suggestions?

[Sillyoldman]

It sounds like your cable is old, I'd chuck a new one on.

[71swb4x4]

Exhaust manifold isn't the worst spot, but I most commonly see them on the top left bolt hole of the passenger side head.

[rocknss]

The negative battery cable should be connected to the engine block as stated above.

[nlped]

Yep, connect the ground cable to the block, but also be sure to have plenty of ground straps elsewhere. i.e. block to frame, frame to cab, frame to bed, etc. Can't have to many grounds for sure!!!

[c10boob]

Ok great! Thanks for the help. I'm thinking the main source of this problem was the ground straps, which is a new concept to me since I'm terrible at wiring and new to most of this, hence my username

Thanks again.

[rdgt67]

Had similar problem.ground was to ac bracket. Who je truck was dead. Ran ground from bracket to frame and problem solved.

[c10boob]

Yeah that's got to be it. I went out and looked and I can't see ANY ground wires from the engine to the frame. I'll have to crawl under and give a better look later, it started raining on me.

[rdgt67]

My issue started after I changed a worn out motor mount. I figure the mount was providing the ground then I changed it. Mine wire was nothing fancy just a piece of 10 gauge .

[litew8]

I think it's usually engine ground to firewall. Two of them, one for each head on the back.

Originally Posted by c10boob

Yeah that's got to be it. I went out and looked and I can't see ANY ground wires from the engine to the frame. I'll have to crawl under and give a better look later, it started raining on me.

[rdgt67]

I have a 6. There is a wire from head to firewall but wasn't to the frame. I troubleshoot with a circuit tester and a simple jumper.

[litew8]

Don't think the engine grounds to the frame (with straps) - but it does indirectly by being bolted to it, and that the two in the rear to the cab - the cab is grounded to the frame with strap underneath (pass. side I think). Make sense?

[rdgt67]

Electrics are my shortfall. I went from no power to full service with 14 inches of wire. Beats me why but it worked.

[Lee H]

I use a short battery cable between the outer starter bolt and the frame, makes a great ground between the engine and the frame.

[litew8]

The car's chassis and engine block actually function as part of its electrical system. The battery's negative terminal connects to the car's frame via a short length of cable, as do the electrical accessories and engine block [via motor mounts and straps to firewall]. Electrons flowing from the battery's positive terminal flow through the ignition system, chassis lights, dashboard, fuel pump and anything else that uses electricity, and back to the battery through the metal chassis. Using the frame itself as part of the electrical system cuts by half the amount of wire required to build the car.

Read more : http://www.ehow.com/info_12185174_ca...trap-work.html

[Fitz]

Your ground straps should be the same gauge as the positive battery cable to return the current from the starter. Anything smaller than the + cable causes too much voltage drop. I used #2 stranded copper to strap the cab to the frame at one of the cab mounts and one on each side of the block to ground the engine to the frame. Since my batteries are behind the bucket seats, the ground strap on the battery goes to one of the seatbelt bolts.

[litew8]

Here's a good thread describing the locations. link
It also shows the mysterious strap in the rear of the bed that I have but is busted.
I didn't know there was a factory strap for bed to frame.

This is what the factory ground straps look like/size:

Originally Posted by Fitz

Your ground straps should be the same gauge as the positive battery cable to return the current from the starter. Anything smaller than the + cable causes too much voltage drop. I used #2 stranded copper to strap the cab to the frame at one of the cab mounts and one on each side of the block to ground the engine to the frame. Since my batteries are behind the bucket seats, the ground strap on the battery goes to one of the seatbelt bolts.

Fitz, not sure that size is necessary for all the ground straps (not that it would hurt any) - but yes, the negative battery cable to frame or engine should be the same gauge as the positive battery cable.

[Fitz]

Originally Posted by litew8

Here's a good thread describing the locations. link
It also shows the mysterious strap in the rear of the bed that I have but is busted.
I didn't know there was a factory strap for bed to frame.

This is what the factory ground straps look like/size:


Fitz, not sure that size is necessary for all the ground straps (not that it would hurt any) - but yes, the negative battery cable to frame or engine should be the same gauge as the positive battery cable.

too large a ground won't leave you stranded. Can't say the same for one that's too small.

[litew8]

What's more important is good connectivity (metal 2 metal). No rust/paint.
The smaller sized straps are just used to ensure overall connectivity collectively,
whereas the largest one via the battery is to guarantee the battery receives it generously.

[c10boob]

Thank you all very much for all the pictures and advice. Now that I have a better idea of what I'm looking for maybe I'll have better luck.

And litew8, something you posted about the gauge of the wires could be my problem. The positive battery cable was a 2 gauge, but the negative was a 4 gauge. It'd be nice if it turned out being that simple.

All in all my truck has had owners do some strange things to it, especially with the wiring. Much of the wiring isn't even hooked to fuses, so I'm trying to learn what I can and correct it all before something catches fire

When I get some time this week I'll look into everything mentioned above and post back as to what my final solution was.

[litew8]

Sounds good man ironically, I'm dealing with lighting/electrical issues too

[c10boob]

I'm not seeing grounding straps anywhere leading to the engine of my truck, so at least as a temporary fix I've replaced and moved the negative cable from the exhaust manifold to the frame and the cable is no longer getting hot and the truck is starting a lot better, though about every 5 starts still gets a click from the starter/no start.

[litew8]

Ensure the starter/solenoid is wired correctly. Good move to the frame.

[volksworld]

dont just move the cable to the frame unless you have an equal sized cable running from the frame to the engine block...straight to the block is the preferred method for max starter current, then block to frame powers the rest of the truck's electricals