Electrial wizards plz read... Cranking car and ground wire melted.... more.....

check ur hots, somethings been grounded.

been in your shoes, done that... not with a 5.0L but with a 4 cyl. The starter is either wired wrong, or it's bad. The car is frying the small wire because that wire does not have a fusable link (as it is a ground wire, FL are only on + wires) and there are no fuses and/or breakers, nor any kind of voltage protection on the 2 main battery cables. If the engine was cranking over, you might want to check for a bare spot on the positive cable that leads to the starter, from the solenoid. That cable is only hot when you engage the solenoid, by turning the key to the start position. a way to test this is to get a DVOM, hook it up to the post on the solenoid that goes to the starter, and check for continuity to the ground post on the battery. If you get a reading of anything close to zero or 00.0 you have a problem. Some DVOM's have a buzzer for continuity, if yours does, adn you hear it, start by disconnecting the cable from the starter, and recheck. if you still get it, take the cable off the solenoid on the starter side (side not connected to the battery, and then check for continuity to ground on teh cable, with it disconnected. eventually, you will find your sore spot, it just takes some time and coffee. Hope this helps.

make sure your battery is hooked up properly. i did that once in my truck. ooooops.

Make sure there are no wires pinched between the motor mounts and engine or MM and frame. Same thing happened to a friend and that was the cause.

More than likely it's your starter going bad. Get a new starter and cables and I'd be willing to bet no more problems.

i agree, my starter melted the terminal off the solenoid before i could realize it was bad

For sure your hot to ground but not always. Trace the starter.....again, and look for shorts or even rewire it with 4-8 gauge wire and it it burns that ground wire again, change the starter. I can't imagine anything that hot only on crank except the starter or starter cable to ground, $5 its the starter or cable.





LOOK man I'm 666!!!!

I have the Same Problem

1993SSP said:

Ok, here's my question! I was cranking my car after engine swap tonight, while trying to get the car started smoke started coming from near the battery, the small wire that runs off the battery ground over to the inside fender wall freakin melted the covering off?!?!?! Any insight on what caused this? The main ground wire is still perfect. Also I noticed that sometime in the past the covering on the wire to the fuseable link for the fuel pump has been extremely hot and melted in the past (from a previous owner) and has been spliced together, anyone know what could cause these problems? The last thing I'd want is a electrical fire. Any pointers are appreciated.

Click to expand...

I have the same problem as you. And I think replacing the Ground AND starter cables IS the solution. Mine is an 1986 5.0 LX. I pulled up the wiring diagrams from ALLDATA (nifty online subscription). Heres what the wiring Diagram tells me.

The 10 ga. wire that comes off the Battery (small one) goes to Ground G116.
Then it goes to Connector C149 (about 12 inches after the spot screwed to the fender).

After C149 the wire turns from black to Blk/Lt. Green. Then proceeds to Splice S131(In harness near connector to battery). From there it splits (inside the plastic tubing) and goes to pin 40 & 60 on a Solid state gizo, as well as to the EEC (electronic Engine Controll), fog lamps, EEC power relay, and Left & Right Heated EGO Sensors. The EEC basically controls every sensor and gizmo on the engine.

So what is hapening, is one of two scenarios:
1. The Big RED cable going from the starter solenoid to the starter, is chaffed and overloading the little 10 ga. wire.

2. The Big Black Cable going from the negative terminal on the battery to the engine block, is corroded. The result is Every electrical gizmo on the car is grounding through the litttle cable instead of the big thick cable.

I'm going with senario #2. Otherwise The Whole wire all the way up to the ECM would have melted, instead of just the portion that went from the fender to the battery terminal.

I Hope this helps everyone that has this problem.

Yep, what happened is the large ground wire was not grounded well enough and had a higher resitance than the small EEC ground strap to the fender, so WAY too much cranking current came back to the battery through the little wire rather than the big wire. It's called "ohms law" - current takes the path of least resistance.