I have a 2008 Chevy Silverado LT 2Wheel Drive 5.3 ltr V8 and it's acting up it seems to have an electrical issue. When I'm idling at work after a hour-long drive and it idles for about 30 minutes all my gauges start to fluctuate go up and down and the car shuts off it's done this twice in one week. And on my way to work Friday the car completely died at an intersection no power at all couldn't even put on my hazard lights it was like someone had taken out the battery. The only thing I have had done on the car is a shop said that the main wiring harness was grounding out onto the frame and they quote unquote fixed it. Do you think maybe they didn't fix it correctly. Would you suggest changing out the wiring harness or do you think you'd be able to repair that wiring harness? It has thrown out various check engine codes including ECM TCM and BCM error codes. It also sometimes when I turn off the truck and take the key out the truck continues to run for 5 to 10 seconds before rough idling down. Do you think this would be a ground issue or could it be the wiring harness that wasn't properly done?
Clarification: Mileage?
150,000
My bet is the shop forgot to connect an important ground strap.
I am with @toyotagrl on this one. Check especially under the drivers door on the frame rail where a bunch of grounding connectors are supposed to be. Because of its exposure to the elements, this grounding connection area is the source of many electrical problems for your era truck. Make sure the connections are clean, metal to metal and tight.
I turn off the truck and take the key out the truck continues to run
bad ignition switch
Already been replaced with new one. That was one of the first things we did.
ok can you please list ALL the troubleshooting and all the parts your replaced please. That way we're not both wasting our time with stuff that was already done. Thanks.
New alternator ,battery, new ignition switch. Checked all the fuses. Had the wiring harness "fixed". Starter checked out fine. The problem comes and goes as it pleases which is not what I need nor want with a vehicle I take out of state.
It was taken to a local mechanic I trust and I was told after hours of searching...my amp was switched to DC and was sending voltage back into the truck. Does this seem likely to cause the issue of just dying while driving and the truck still running after the key has been removed. Thoughts!?