GMC Troubleshooting Questions? Ask a Mechanic for Answers
Welcome, I'm Chris (aka Moose) I prefer to work when others don't, I am here around lunch and after dinner till after midnight.
Most likely these issues are not related. This is going to take some electrical diag to figure out using the links below. Can you do electrical diag?
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To isolate IGN3 unplug the heated seat switch., rear HVAC control in rear center console, rear temp and mode door actuators also in the console.
Hello again Chris here,