hard cranking, melted ground wire...

[COCHEV]

Went to start the truck this morning and she would barely crank over. Then I noticed smoke coming out from under the hood. A ground wire from the neg to the core support just about melted. Must have developed some kind of direct short somewhere?

 

[Fordum]

Must have developed some kind of direct short somewhere?

Nope, just the opposite. You developed an open.

That wire will never carry the load of the starter. But it was not designed to. That is what that big wire its attached to is for.

The fact that it melted, means that the big wire lost contact, and the little wire was the only ground source, so the starter load tried to go through it.

Take the big ground wire loose from where it is attached and find out why its not making good contact.

And its best if you replace the little one.

Its also possible that the big wire is solidly attached, but whatever it is attached to does not have a good connection to the stater housing.

But there is a bad connection somewhere between that wire and the starter.

 

[DokWatson]

Happened to me once...the wire going to the starter melted to the headers. That was fun.

 

[COCHEV]

Thanks for the replies. I didn't have time to scope it out this morning- had to hop in the blazer and get to work.

The large ground wire goes to the alt bracket. Maybe its simply loose or corroded. Guess I know what i'm doing after work...

 

[COCHEV]

Nope, just the opposite. You developed an open.

That wire will never carry the load of the starter. But it was not designed to. That is what that big wire its attached to is for.

The fact that it melted, means that the big wire lost contact, and the little wire was the only ground source, so the starter load tried to go through it.

Take the big ground wire loose from where it is attached and find out why its not making good contact.

And its best if you replace the little one.

Its also possible that the big wire is solidly attached, but whatever it is attached to does not have a good connection to the stater housing.

But there is a bad connection somewhere between that wire and the starter.

Thanks man, you nailed it. Bad connection/corrosion on both cables. Replaced em both. Back on the road

 

[Fordum]

Thanks man, you nailed it. Bad connection/corrosion on both cables. Replaced em both. Back on the road

Fantastic.
You know what they say, even a blind hog.............

If I keep posting ideas, sooner or later I'm bound to get one right.

But, I cheated a little on that one. I had seen it before and knew that the starter load was trying to go through that small wire......

 

[79rustyk10]

I always try to put the ground cable to a cylinder head somehow.

Too many issues putting it on the alt bracket that ive seen

And more ground wires are never bad, I killed a shifter cable in my Nova once due to not having proper grounding. It started on fire, suprisingly big fire for that little cable too.

Now on projects, I add one from the body to the engine, and the engine to the frame just for good measure, on top of whats already there.

 

[Fordum]

Yeah, anytime I am rewiring a rig, I try to hook the ground to the block somewhere, since the starter is the biggest load and the better the connection to it, the better in general.

BUT, I also try to run a heavy ground to the alt. bracket. It needs a good ground too.

 

[Deuling]

I just re ran my ground wire to the block on one of the 2 holes by the fuel pump. seems like a good location out of the way from heat and moving parts.