rowdyroost

I had a crazy situation. The metal bracket that holds the battery in place managed to slip loose and fall over and touch the hot post on the battery. Since the other end was touching the frame it created quite a mess. Smoke came out from the hood and it basically fried my computer and also managed to get hot enough to fry my parking brake. We've tried another computer (old used one) and it basically got fried, too. So, we're thinking we need another wiring harness for the engine.

The part number needed for my '94 truck is 82121-35262. I've found a wiring harness on ebay for the right price... however, it's listed for a '93. Part number on it is 82121-35261. I'm trying to figure out if I might be able to make the '93 part work on the '94. Everything matches up as far as 4wd/manual/v6 goes. Just curious if anybody has experience with this.

Thanks

KBAM

No hands on experience with the harness swap from me, but from what I understand the trucks had little to no change year over year.

wyoming9

iTrader: (1)

You might want to figure out just what the problem is.

Just how did it manage to fry the emergency brake ?

If it took out the ECU then the cab harness is most likely melted as well

rowdyroost

I originally had it towed to a mechanic and they said the computer and engine wiring harness would need to be replaced. As well as the parking brake cable. I'm not beginning to worry about the parking brake till I get it running. Everything in the cab seems to be working as it should. Radio, speedometer, RPM's, lights, etc... are all ok. Granted... problems may rear their ugly head later.

RJR

Shorting the battery to ground through the hold-down bracket will indeed create a lot of smoke and sparks, but the damage should be limited to the battery itself and the bracket. No particular reason the computer or the wiring harness should get fried. Nor is there any reason for such an event to damage your e-brake cable unless the whole vehicle caught fire and burned to the ground.

You say the "RPM's" are working in the cab. Does that mean the engine runs? Be a little more specific about what works and what doesn't. Right now I don't have a lot of confidence in your mechanic based on what you've reported.

rowdyroost

Yes, the truck runs. It just sputters and dies after you move a bit. I was in the vehicle driving when it all happened. Smoke started coming out from under the hood (around where the battery is). I pulled over and immediately lifted the hood. A lot of smoke, popping, and sizzling. Definitely the distinct smell of burning plastic/rubber. It died out after a couple of minutes and then smoke started coming out from the rear tire well (parking brake). I was thoroughly confused at the time as to what was going on.
The smoke wasn't stopping from the tire well area so I called the fire dept. They came out and sprayed the underneath of my truck, and then they figured out it was the bracket that had touched the post. All fuses looked OK so I thought maybe I had dodged a bullet and only had parking brake damage.
I cranked the truck... It started fine. Idled smooth. But when I shifted it into gear there was a slight hesitation. When I hit the gas it started sputtering along a few feet and it died. I could crank it and repeat the process. So, had it towed. However, since i got it back from the mechanic, now when I crank it... It sputters at idle too. Distinct smell of gas when I shut it off.

RJR

If the truck runs the computer isn't "fried". It's possible it got damaged, but I'd be looking elsewhere first. First thing to do is to check for diagnostic codes. There are a couple of links to the online service manual at the top of this forum. Go there and drill down to "Engine - 3VZE - MFI-diagnostics" to find out how to check for codes and what they mean.

Also check for obviously burnt wires in the vicinity of the battery. And don't rule out the possibility of wet electronics or electrical connections after the fire department got done hosing down your truck. Might be just a case of wet distributor cap and spark plug wiring. Take that stuff apart and make sure it's good and dry.

Don't quite know how to explain the parking brake problem, except that maybe when the original battery fire started you got excited, pulled the parking brake without realizing it, and then kept on driving. Whatever the case, the parking brake is not part of your electrical issues. (and darned if I know why "parking brake" shows up as a hot link in my post.)

rowdyroost

The fire dept only sprayed water underneath the truck towards the back along the emergency brake cable. I didn't pull the emergency brake cable at any point. Even if I did, I only traveled about 25 yards after the smoke showed up (and I was only going about 25 mph). Not a highway or anything.
I believe I've chosen a bad choice of words by saying "fried". I should have said "shorted". I will check out the wires more closely and look into the computer codes.

wyoming9

iTrader: (1)

Now when you had this dead short it should have returned back to the battery via the ground going to the inner fender.

As that would be the shortest path .

That should have flowed till the battery was dead or the hold down melted or the ground cables melted causing a open circuit.

You should check all the ground points for melted wires.

That might be the cause of the poor running.

The emergency brake getting hot may have been just bad timing.

rowdyroost

This may explain why the current didn't run to the fender.

scope103

This sounds like a "brush off." Your truck is a mystery to be solved, and the mechanic didn't want to get involved in it unless you were prepared to spend big. Don't blame the mechanic; he just didn't want to do it.

I agree. And you're a long ways from saying your problem is in the computer, or even in the harness.

A shorted battery can put out 100amps for a few seconds. Once it disintegrated the ground wire shown in your picture, it had to find another return path. Who knows, the parking brake cable may have been what it found, smoking the grease around the wheel.

I'd get down there and clean it up where the smoke was. You might find a bit of fried parking brake cable, or something else.

As to the running problems, be systematic. Like RJR says, the codes is where you will start.

rowdyroost

Yeah... Pretty nasty. This is the parking brake cable. I will check out the link on codes and see what I can make sense of. Thanks for all the help and I will update what I figure out.

RJR

I guess more bizarre things have happened, but this is right up there. It would seem that indeed the parking brake cable somehow became the major ground conductor during this battery fault, but given the widely separated locations, it's sure not easy to see how.