Mind teaser, tech issue..

[falconbrother]

Fishing for your thoughts. My 1500 Suburban has recently started acting up. A couple of months ago I released the parking brake and the dash lights lit up like a Christmas tree and it put it's self in 4x4. I restarted, everything normal. A week or more ago the security light started coming on while driving. In the last few days more lights have started coming on while driving,ABS, seatbelt, low fuel, gas gauge bouncing around, no tow haul, battery light and AC fan speed constantly changing. I pulled the dash apart looking for a short, tried a new body control module, cleaned a few grounds, had the alternator and battery tested. All good, issue persist. I discovered today that when I turn the AC off, all the issues go away. So, it seems to possibly be a power issue related to the AC.

We're going camping Thursday. I'm going to pull the camper and let my wife bring the dogs in her car (with AC). Where should I look next? Maybe a ground specific to the AC? Suggestions please? I just refuse to let this thing beat me..

[Ron3rd]

falconbrother wrote:
It's fixed and I towed the RV last Thursday. It was the ground from engine block to computer. My mechanic found it fast, fixed it and added a ground. I'm puzzled as to why Chevy didn't find this. So was my mechanic..

Be sure to leave the incompetent dealer a stellar online review

[falconbrother]

It's fixed and I towed the RV last Thursday. It was the ground from engine block to computer. My mechanic found it fast, fixed it and added a ground. I'm puzzled as to why Chevy didn't find this. So was my mechanic..

[hawkeye-08]

Had some flaky things happen on my 2011 GMC Sierra, found a mouse nest under cover on engine.. cleaned it out, found the insulation eaten on several wires, and one wire was mostly gone. I taped the wires with missing insulation, repaired the wire with piece missing. I then connected my OBD tool and reset the code it had set. All good, that was a couple years ago now.

[bucky]

A suburban of your year also has a body control module. I'm still leaning towards a cluster issue. A rarity, but a intermittent alt problem left me scratching my you know whats a few years back.

[dodge_guy]

Electrical issues are what would total an other wise good car. The labor alone to try and trace down a bad wire or odd issue is what makes some vehicles not even worth fixing. If the vehicle is worth the $$$$ then definitely put the money into it!

[ls1mike]

I missed the year and mileage. I have had a BCM (Body Control Module)cause issues like that.

[Fryer5]

I fought electrical gremlins in my last suburban. Some things to check:
1. The ground from the body to the engine is notorious for going bad, easiest fix is to add a new one from the fire wall to the engine block as the original bolts to the back side of the engine.
2. The battery cables go bad. Bad crimps? Poor design? Don’t know.
I ended up replacing my OEM cables with new ac delconcables, wasn’t cheap but I DIY’d it.
I also cleaned every connection point with a brass brush and used a liberal amount of dielectric grease during reassembly.
I had also read reports of the main fuse panel in the engine bay corroding, you can pull it, Clean and grease it as well.
My suburban was a 2008 2500 model, but a lot of this applies to all suburbans those years. Good luck! In the end I traded it for a Nissan.

[falconbrother]

Well, Chevrolet was able to tell me that the computer(s) are all OK. They said they fixed it during the diagnosis and it rode right for two miles. Then went nuts again. I fooled with it till 9:30 last night. It was running perfect. Get up this am. Wont even start. Just makes weird noises and a slight thumping noise through the stereo. I wiggled harnesses and made the noise get faster. That's it. Had it towed to my usual shop. They are pretty good mechanics. I have never seen anything like this. So frustrating. I'm afraid this things about to be towed to the U-Pull-it.

[drsteve]

Sounds like low voltage. Instrument cluster or bad ground.

[FishOnOne]

Dash cluster is a known problem with these trucks.

[mich800]

Troubleshooting something like that can be difficult without the right tools/scanners. Things that seem causative are only coincidental and lead you down a rabbit hole.

[falconbrother]

I went around last night cleaning up ground points. It's worse today. Violated my own rule and am at Chevrolet now letting them diagnose. I think it may be the ECM at this juncture. I don't want to just throw parts at it.

[Bigfoot_affair]

bucky wrote:
Bad clusters can do some crazy things. A loose ground can drive you crazy. Anybody worked around the engine area recently besides you?

X2, look for a bad ground.

[bucky]

Bad clusters can do some crazy things. A loose ground can drive you crazy. Anybody worked around the engine area recently besides you?