So much crazy electrical errors i dont know what to do!

[Doubeleive]

Thanks for the nice tips! Will get around asap.
Today my odometer blacked out aswell, even though the speedometer is not working my cruise control is
Any tips on how to find a re-furbished cluster on ebay/amazon(or any other)with KMH instead of MPH?
Will probably cost me 2000 dollars to buy it in norway so i will most likely buy from the other side of the pond for a 10th of the price

you can find clusters on ebay that are kmh, there are some sellers that will program the mileage/kilometers and your vin number

 

[LEDFoot]

Hej på dig! Är det inte lag på att alla måste köra elbil i Norge?

With all those issues I would assume that you have something common that is causing all or at least most of it.

I have the same age truck (though in different climate), and I am seeing a lot of issues due to moisture and oxidation of switches and connectors in mine. For example the light switch, I couldn't turn on the headlights manually, and the interior lights only worked while holding the switch in place. Took it out and cleaned it up with some contact cleaner and everything was fine... Connectors and relays and bulb sockets may have the same issues.

As far as your instrument cluster, if it is truly bad (needles not working, lights out, etc) it's relatively easy to replace the stepper motors yourself and replacing the bulbs with LEDs while you are at it. That way no worries about KMH/MPH or anything like that.

Lycka till!

 

[WYO-HD]

As others have mentioned, ground wires are key. My 04 Denali has 200k on it and a while back started doing everything you described and more...hit bump and error messages pop up, locks cycle, gauges quit working, engine going into limp mode, battery drain, etc.

I replaced a bunch of things including remanufactured instrument cluster, battery &TPS. Didn't fix a thing. I then took it to a GMC dealership who replaced every ground wire on vehicle. I think 5 or 6 straps replaced but can't remember exactly. That seemed to fix most issues but would still have gauge cluster intermittent problems...cluster lights not working, some gauges freaking out over bumps and loss of all display features.

Back to the shop and the diagnosis was bad pig tail harness plug behind instrument cluster. It was replaced and now my Yukon is fun to drive.

I was very frustrated and finding the two main issues was gratifying. I know many of these vehicles have the same issues so hopefully this may help others.
Cheers,