Tahoe Electrical Problem

[ksmith]

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.

[1999 Tahoe 4x4]

The fact that your battery terminal gets hot is no good news. I would check with a high amp meter what is the amperage flowing through the wire in this condition. If the amp is high (50amps and plus) you have a serious short somewhere. Look for cover. If the amp is small then you have some bad connection at the terminal. It is entirely possible that your battery terminal is broken internally and has an intermittent connection as you have mentioned that earlier a new battery fixed a similar problem.

 

You have mentioned a sound system and you have disconnected it? Are you sure you have disconnected everything and are you sure the people who put it in did not make any other modifications like splicing cables etc?

[GM-Tech]

Sounds like a connection problem. High resistance = heat. Seems obvious, but is the cable tight enough that you can't move it with considerable pressure?

 

Do you have one of those where there are two positive cables, separated by a spacer? We have problem with those spacers. They seem to shrink in length and no matter how much you tighten the bolt, the cables can be moved with a little hand pressure. We keep the spacer in stock and replace 'em all the time.

[HALO555]

Whatever became of this ? My 2002 Yukon seems to be having a similar problem.

[Wingnut]

Every time I've had my cable get hot, and the truck exhibit bizarre electrical behavior, it's been a bad cable. It's always looked good on the outside and at the ends, but the cable itself is falling apart inside the insulation.