I can't find the ground wires in my Envoy - 2003 GMC Envoy

https://s15.postimg.org/taongnt97/Untitled.jpg

Click on the link, hope it works?
Yes, it is a partial diagram. Check voltage and ground, see the fuses, not only check the fuses, check the fuse circuit for voltage. Use a test light. Some fuse circuits are hot all the time, some go hot with the key on. Also, check the ground, black wire with white tracer in diagram, should be chassis ground, check the way you would any chassis ground.
Any applicable trouble codes? As far as your gages, the pcm sends serial data to instrument cluster telling ipc what to do with gages. I can't rule out instrument cluster itself, at the moment.

1 side of the fuse is ground. Ck emissions, clogged exhaust, throttle positioning sensor, fuel PSI, vacuum leaks. Scan the PC for codes & go from there

Does your husban know how to do electrical testing ? Find a wiring diagram , voltage drop test the circuit to find what's missing power or ground . The hit could have damaged wiring or ground . You can find a wiring diagram at http://www.bbbind.com/free_tsb.html Also watch youtube video on Mastering Voltage Drop Testing with Pete Meier and Jerry Truglia .

May not be the module, or fuse. ALWAYS check the ground on this stuff first thing. If need be, take a piece of wire and hod the bare ends on the ground connection and other end on a clear spot on the bumper and have someone push the button to turn on the wiper. A good spot would be where the wiper comes thru the door to hold the wire on and other end on bumper to test ground fault.

Vehicles have many ground wires

Need a factory service manual or go to a repair
shop & look in their data base

Check the white ground wire on the plug on the vehicle.

check wires if the is ground connection ,then check for wire miss connection. But then rain moisture can give effect on the radio and wiper if the is a grounded wires.

it may maybe a ground problem with a brown ground wire in the harnes

Hi there;

Here is the wiring diagram for the trailer wiring for your truck.

Hope this helps
Farrout!

by looking at the wiring diagram for your truck. the pcm1 fuse only feeds the pcm so most likely it is a grounded wire between the fuse block and pcm. follow the wire harness closely between the two and see if its grounded somewhere. also try disconnecting the pcm and see if the fuse still blows. that would isolate the problem to the wiring. it is highly unlikely that the pcm would cause the problem.