Okay. That is what I was going towards. I agree that the issue is most likely power. I attached the wiring diagrams which show the power feeds for the radio. We can check the radio/Onstar fuse in the rear fuse block which is under the rear seat. If the Onstar system is not working either then this is where you start.
If not, then we need to check power at the radio and find out if we have a wiring issue. Basically if you have power on the fuse but nothing at the radio it would have to be a wiring issue.
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Tuesday, February 4th, 2020 AT 6:13 PM