Ok here is a weird one. Have a 07 silverado with factory radio and cd player. Radio works and then does not work. Or I should say it works but ...

Ok here is a weird one. Have a 07 silverado with factory radio and cd player.

Radio works and then does not work. Or I should say it works but at a very low volume level and only through the roof post speakers. Also noticed that when the radio is haveing this issue the open door chimes also are very weak or do not work.

Then it may come on and everything works. Very fustrating.

My guess would be the radio is defective. In these vehicles a lot of things run through the radio.

Got to be ther radio. I have a similar problem but with just the front channels.

I had similar problems. One day no radio and also no chimes, since the sound comes through the speakers. I also had a noise sounding like a muffled air leak coming from the passenger side. It was intermittent of course, making it hard to diagnose.
My brother-in-law looked under the hood and said my alternator was making noise, and it was probably the bearings. I had it replaced and to my surprise, radio back on and working better than ever. The pulley on or next to the alternator needed to be replaced also, since it was the cause, most likely from bearing down on the alternator for so long. But I do have 318,000 miles on my truck and never had the alternator replaced. Nothing led us to believe it was the alternator. It was a quick fix and now everything is brighter, including my headlights, which I didn't really notice until now.
Hopefully that helps some people out!