Hi All,

In the process of outfitting my 2010 Express 1500 and made a major bonehead move. Drilling through the floor to put in an external propane heater I cut right through the body harness next to the passenger side cargo access door. I remade the connections and soldered them back together, shrink wrap, checked the resistance, the whole 9 yards but still getting some issues. The van was off when I cut the harness but immediately got responses from the door locks. Ongoing issues are:

Turn signals / Hazards don't work - rear wires aren't receiving power have not checked the front but assume the same; not getting anything from the lever or the instrument panel
Door lock controls on driver and passenger door aren't working but door locks still work from the key fab
Windshield washer control automatically activates every other time I turn the car on and am not able to turn them off without turning off the car
Airbag dummy light on - assuming from the passenger side impact sensor

My brake lights still work, reverse lights still work, horn etc.

I already checked all the fuses and strangely enough none have been blown but a significant number of fuses aren't receiving power. I know that some of them are obviously only going to get power when in use but I am wondering if there are larger "master" fuses that occur somewhere along the circuit before they get to the main panel under the hood or under the seat that night have blown?

I can't figure out why some issues are not getting power without a burnt fuse and why the washer is self activating. The washer fuse only get's power when it turns itself on otherwise not getting anything from it if I try and activate it manually.

If you have any ideas on where to go from here I am all ears. Thanks!

 

did you check both fuse boxes?

 

I cannot imagine you causing too many issues, from what I recall everything is fused and there is only two fuse boxes. Everything you cut should be on the fuse box under the seat. I suppose the one thing you might have done is friend parts of the computer which sits below the passenger airbag. Perhaps you grounded, or send power through circuits not designed for such. Like your door sensors? Anyways, there are no other fuses. I would just trace each wire, make sure each is good, check all the fuses, and from there... probably consider that maybe the computer is fried. It's all simple stuff. I recommend clicking the link in my signature, finding your year of build and studying the schematics yourself.

 

Thanks dberladyn,

I have checked both fuse boxes. Best I can guess is that we fried the BCM under the glove compartment as that seems to be controlling everything that is going wrong, however the single fuse in the computer is not blown.Having a mechanic install another one so it can be programmed. Don't want to turn my rig into a paperweight. Appreciate the schematic. I am hopeful I didn't cause a ground but that is fairly likely given that blade probably touched the chassis and the wire at the same time. If that is the case, what would I be looking for? a melted wire somewhere along the harness?

 

If you remove the computer and you open the plastic case, you will find that it is simply a circuit board with chips on it. You might find something, you might not. But if it was me I would take the computer out and inspect it for blown components. I don't think the juice on the wires you shorted is near enough to melt wires or do any of the damage you suggested. It's likely fried chips, blown transistors, resistors, capacitors, diodes, etc on that circuit board. I would make sure that all the wiring is good. That everything is connected to where it should be, and replace the computer. That to me sounds like the most realistic step to take. I have two spares here, but I think they are the wrong year for my truck. I would love to install a different one with different programmed options. I want my onstar gone. I cannot remove it because of the computer and it's program.

Incidentally, there's a chance your computer is fine and it just needs to be re-flashed. I don't know, but I can see that being the case.