Tahoe Electrical Problem

Hello-
I've been having a problem lately with my 4DR 4WD Chevy Tahoe. Lately it has been completely losing electrical power while driving or sitting at a light. Everything is running fine, then it just shuts off. All lights, everything. When this first started happening, the truck would start right back up. Now, however, it stays dead until I remove the positive battery cable (negative doesnt help). When I put the pos. cable back on, there is enough juice to crank it back up. There is no corrosion on the cables, but I noticed the last time this happened that the positive cable terminal was extremely hot and the stock red rubber around the cable end was starting to melt/burn. Ive had the battery and alternator checked out and they tested fine. Had a general mechanics shop look at it all day today and they couldnt reproduce the problem, so they didn't figure it out either. I've got a nice Optima Yellow-top so I don't think the battery is the problem.

Last summer, the car was doing almost the same thing. The only difference was the terminals were corroding badly. I had the battery check and they said it was bad (another Optima yellow top, only a year old), so I got it replaced. It ran fine until this current problem arose last month.

Lastly, when I bought car 3 years ago, the alternator died and I had it rebuilt to a slightly higher output (to power my sound system, which is now unplugged to eliminate that as the problem). Could this be damaging my electrical system?

Thanks for taking the time to read this. Hopefully someone has an idea of what's going on, but I realize electrical problems are difficult to diagnose, especially over the net.

Well here's my take on it. The heat you mentioned on the Pos cable could come from corrosion that you can't see inside the cable causing high resistance. Everything else has checked out for you, so I'd replace both Pos and Neg battery cables and see what happens..........Steve

Like Stickman says, you've got resistance in (at least) the positive cable connection.

You didn't mention what year your tahoe is, your profile says 1998. I believe that year has the double-cables at the positive terminal. If it does, check the lead spacer that goes between the two cables for wear/corrosion/melting. If that spacer is too thin the bolt will bottom out, and the cables will still be a little loose. Loose enough to get hot and become intermittent.

Make sure the cables are secure when the bolts are tight. You shouldn't be able to move them.

I had similier problem where the spacing go to large and had to replace the positive cable on a 99 tahoe