1999 durango, 5.9 engine, 4wd. Recently found a 6 gauge black wire loose. No idea what it connects to on either end. It is next to the battery, has sparked against the positive post, and enters the wiring harness at the same point that the 6 gauge wire from the power distribution center enters the wiring harness. Since it is "obviously" a ground wire, it it safe to just hook it to the negative terminal of the battery, or to a random bolt on the engine/frame? What does it go to on the end that is buried in the harness?

 

That does look like a ground. Why the heck would you brush it against the positive post though? You're begging to fry something or at least go chase down a fuse.

 

certainly wasn't intentional! Wasn't even done when we had the hood up, just randomly brushed against the post while driving, which is how we found it, when all kinds of problems arose from that. Can't locate any evidence that it was ever attached to anything, yet it had to have been for it to be running for all these years. Any idea what it is a ground for?

 

I would go look at mine, but I have a 4.7L. Maybe someone else will chime in. I'm 95% positive that it's a ground but that 5% makes me not want to be the guy that tells you to go hook it up. LOL

 

hehehe. I do understand that, and that is why I am asking for help. I have the wiring diagrams, yet they don't mention this particular wire AT ALL. And of course, they don't bother putting pictures in those diagrams, or show the actual connection points.

 

That is definitely a ground wire. You're lucky it didn't explode or catch fire when it hit the positive terminal. From the picture, you have the aftermarket repair clamps. It evidently came out of the ground connector. Put a little dielectric grease on it, unbolt the terminal from the battery then unbolt the holding bolts holding the wire clamp. Slip it back in and tighten it down. It's either your engine to battery or body to battery ground wire. From the size, it's an important one. Your truck may start and run without it but you're putting a LOT of power through wiring not designed for it.

 

Thank you!