2008 GMC Duramax - HELP Demon Possessed

June 26, 2022, 06:58 AM

jcsabolt2

I'll try to make this short and sweet.

1) Had $2800 in mostly non-mechanical repairs done on my truck several weeks ago on my truck due to my fuel tank darn near falling off onto the interstate. Thanks GMC for such shitty design/structural steel work!

2) Truck has sat in garage for the past month due to Diesel in my area being between $6.25-$6.50/gal and we were on vacation for the past week.

3) Went to start the truck yesterday and everything that had a light, bell, whistle, etc. that could come on or off did, but the truck would not even begin to turn over or start. Just a lot of clicking, flashy lights, AC kept turning on after I turned it off, etc. Tried jumping it, no dice, not even a glimmer. Several months back I was driving down the road and my headlights turned off. I had to stop the truck, restart it and they came back on. Did that twice, but haven't since. Any ideas?

Thanks in advance!

June 26, 2022, 07:23 AM

xanth

quote:
Originally posted by jcsabolt2:
I'll try to make this short and sweet.

1) Had $2800 in mostly non-mechanical repairs done on my truck several weeks ago on my truck due to my fuel tank darn near falling off onto the interstate. Thanks GMC for such shitty design/structural steel work!

2) Truck has sat in garage for the past month due to Diesel in my area being between $6.25-$6.50/gal and we were on vacation for the past week.

3) Went to start the truck yesterday and everything that had a light, bell, whistle, etc. that could come on or off did, but the truck would not even begin to turn over or start. Just a lot of clicking, flashy lights, AC kept turning on after I turned it off, etc. Tried jumping it, no dice, not even a glimmer. Several months back I was driving down the road and my headlights turned off. I had to stop the truck, restart it and they came back on. Did that twice, but haven't since. Any ideas?

Thanks in advance!

I'd check your battery(ies) first. Take it (or them) out and get them checked.

Then run the ground wires, see if you have a bad ground somewhere.

June 26, 2022, 07:25 AM

ArtieS

That is where I'd start also.

"I vowed to myself to fight against evil more completely and more wholeheartedly than I ever did before. . . . That’s the only way to pay back part of that vast debt, to live up to and try to fulfill that tremendous obligation."

Alfred Hornik, Sunday, December 2, 1945 to his family, on his continuing duty to others for surviving WW II.

June 26, 2022, 07:25 AM

nhracecraft

I would check for a loose ground, make sure the Pos+ & Neg- Cables at the Battery(s) are secure/corrosion free and check Battery Voltage.

____________________________________________________________

If Some is Good, and More is Better.....then Too Much, is Just Enough !!
Trump 47....Making America Great Again!
"May Almighty God bless the United States of America" - parabellum 7/26/20
Live Free or Die!

June 26, 2022, 07:27 AM

egregore

Start with the simple stuff first. Especially if it still has those stupid side terminal batteries, I'd start by checking those connections. They are bad for loosening, which in turn causes arcing and corrosion, and also give jumper cable/box clamps little purchase. Test - or have tested - both batteries while in there. They need to be isolated from each other. And check the charging system.

June 26, 2022, 08:21 AM

cheeze

Pretty sure it’s your battery(ies) and the headlight debacle is a unrelated gremlin

June 26, 2022, 08:40 AM

jed7s9b

Check all around for any evidence of mice. They chew the insulation off the wires and all sorts of things can happen when the bare wires touch.look under the fuse box, under the intake plenum, etc. Look for droppings, trails of filth, fuzzy nesting material, etc.

June 26, 2022, 09:34 AM

Pyker

My Tahoe squad car did exactly that, except for the headlights thing. Bad ground to the chassis.

June 26, 2022, 10:35 AM

rizzle

quote:
Originally posted by nhracecraft:
I would check for a loose ground, make sure the Pos+ & Neg- Cables at the Battery(s) are secure/corrosion free and check Battery Voltage.

Would like to add in 2008, the Silverados had a problem where the battery cables were crimped at the battery terminals. Internal arcing that can not be seen from the outside.
Took me more time than I care to admit to find it, all I should of done was to volt drop test the cables, since the cables looked perfect, I did not bother at first.