Electrical Issue in my 03 Yukon

[Quee]

I have a 2003 Yukon and I have had a weird electrical issue that has been ongoing for a while now.

When I crank the Yukon up, I hear the bell noise and the brake light turns on. Once I turn on my ac that’s when I notice the temperature hand, gas hand, oil and battery hands drop down the first line on indicators on cluster start acting weird. When I decide to roll my window down the cluster flickers and ac briefly stops. It’s the same when I let the window back up the air starts back blowing. I just don’t know what is causing the issue.

 

[DARRYL EDWARDS]

Check all of your body ground wires. I believe there’s three . They may damaged or corroded and damaged.
1-On the driver side firewall
2-Under driver side seat on the frame
3-And under radiator on the frame

 

[NardDog]

These trucks have known cluster issues and often times need to be reworked to fix the issue. Many channels on YouTube show how to repair these when you say brake light comes on. Do you mean the brake light on the cluster.? If so, that’s a complete separate issue With the ABS module under the truck, coincidentally also another Electrical issue I fixed mine by pulling it out and soldering all the joints on the circuit board. Not sure what the relationship is between your cluster and your air conditioning but like has been mentioned you might just check those grounds underneath the truck as well

 

[mattbta]

Check all of your body ground wires. I believe there’s three . They may damaged or corroded and damaged.
1-On the driver side firewall
2-Under driver side seat on the frame
3-And under radiator on the frame

registered 4 years ago and just posted first time! welcome, stay around.

 

[ScottyBoy]

Definitely spunds like a ground wire issue. Double check all grounds connected to the engine block, and all the body/frame grounds that you can find.