Anyone have any issues with the CD player not working on your 2009 Cadillac CTS? Also, when I turn the rear defroster on the radio loses signal and goes static. The lights on the center console flicker every once and a while.
Do the same things happen when in AUX mode, ie, engine not running?
If not, I’d suspect a faulty alternator putting out excessive ripple.
If so, I’d suspect a bad ground in the electrical system, or corroded battery connections.
Having problems with older CD units is a very common occurrence, mostly due to mechanical issues. You will either have to get yours serviced or replace it with another one.
The radio signal problem might be happening because the antenna is incorporated into the rear window along with the heater element. I am not sure of the design for you vehicle. There may also be a RF preamp involved for the antenna.
The window tint on your back window may be conductive and interfering with the antenna operation when the rear defroster is on.