Hi everyone,
I have a 02 Express Chevy Van, w/350 engin.

I went on a dirt road (not bad) and blew the Transmission / Speedometer.

I installed another fuse and it lasted for 3 months until I hit a pothole and it blew again.

This has went on until I could only drive a few miles.

My mechanic is stumped. I live in a rural area, any help is appreciated.

Thanks in advance.

There is no magic answer for find short circuits. It just takes careful examination of the circuit and wiring. Look for any wires caught, jammed or chaffing anywhere. It could end up being a module, solenoid or sensor also.




78 Corvette Pace Car For Sale-18k mi orig-Florida

Thanks for the reply Hammer Time, I kinda thought it was a search and destroy mission.

I was hopping it was a common problem.

I am an electrician, and do have a tone generator. I'm lost when it comes to auto wiring though.

If you can give me a box location and fuse number, I'll try to find you wiring diagram of the circuit. The biggest problem here is that when a fuse powers a module, any module, that module in turn powers other things that could actually be the cause and they won'r show on the fuse circuit.




78 Corvette Pace Car For Sale-18k mi orig-Florida

 
Not sure what number.

It is a 10 amp inside fuse block driver side floor. If you are facing the block, it is the 2nd one "up from the bottom" on the far right.
Thanks.

Sounds like your looking at the fuse box upside down. That would be fuse #20
Instrument cluster
PCM
Transmission

That's about all the diagram reveals. Anything that any of these modules powers could be the problem. Good luck with this one. Unless you can physically see something, this is going to be hell.




78 Corvette Pace Car For Sale-18k mi orig-Florida

 
Just an update; Got the van back frome the mechanic. He found nothing.

I hooked up my tone generator and yep, it goes to the PCM and to the trans speed sensor.

It also goes into the instrument cluster, which I have heard a lot of bad things.

I am an industrial electrician and have rewired large machines and conveyor systems with 1000's of terminations. I never realized how many wires were in the new vehicles.

Great place they put the PCM, right under the break resevore. I wonder how good the unit is sealed.

Judging by the paint missing under the PCM from getting breaks changed, it has been drenched in hydraulic fluid.

Thanks for the leads. If I find it I will post the results.

Hahaha..........

Welcome to our world

Here are the pinout diagrams for the PCM if it helps you












78 Corvette Pace Car For Sale-18k mi orig-Florida

Thanks, I think I will need that.

If I can't find the problem It may be Hammer Time for this thing.

There are some specialty auto electric shops around that are pretty good with that stuff. You may have to resort to them.




78 Corvette Pace Car For Sale-18k mi orig-Florida