When this happens, are there any other electrical components that are acting strange? For example, do the headlamps dim, or the wipers run slowly?
I'm asking because the radio and A/C are on separate circuits and one shouldn't affect the other. Also, I need to know if the radio is a base radio, highline (hands free), and does it have a CD player.
We may have to scan the can bus system to determine what is happening. CAN stands for computer area network. This is the future of vehicles. There are so many different computers and modules in a vehicle, all the wiring would add another 1000 pounds to it. So, they started tying everything together via a can bus. Some of the radios are on what is called the PCI Bus system.
Here is a video that shows how a can system can be checked/scanned:
Let me know if anything other is noticeable.
Monday, July 20th, 2020 AT 6:52 PM