Dash lit up like a Christmas tree.....bad ground?

Offcamber · September 18, 2022

2016 GMC Sierra 6.0 4WD

about 36K on the OD.

First let me start that for years I have had this very intermittent no start issue which I am convinced is the starter or the wiring harness....Battery power is good, hear the solenoid click but starter does not turn over. The solution was to crawl under the truck and smack the starter with a wrench and the truck would the start. I have planned to just replace the starter as I figure there is just a dead spot. However it so rarely does it and this truck sits a lot I just haven't got round to it. "lazy"

The other day I had tires put on ( don't think this is relevant but figured I'd mention it.) They did it in the parking lot with floor jacks so I doubt my current issue has anything to do with that.

Anyway the other day I went to move the truck and no start again. Since I didn't really need it and it was raining I figured I would just leave it for the time being.

Today I went ( outside temp is much warmer today) to start it and it fired right but then the dash lit up with almost every light. All kinds of transmission codes back up camera didn't work engine ran kind rough no ABS or TC. Threw the scanner on it and you can see the diagnostic report below.

I figure all these modules can't fail at once...So it sounds like bad ground somewhere. Everything is good at both batteries.

Shut it down restarted and everything cleared. Took it to get gas with no issues.

So my questions is where is the best place to start looking for a bad or loose ground??

A buddy has a lift so I am going to try and get up under there and probably replace the started while I'm there.

Thanks

Yotaman · September 19, 2022

Watch this may pertain to you.

Yotaman

jthoske · September 23, 2022

Check the voltage drop in your ground wire. Mine just went bad in my 2018 Silverado LT 5.3. I have not looked at the chassis ground as the video above just found. The dealer wants to replace the negative battery cable for $500+ and they are on national back order and OOS everywhere (called a dozen places or more)