ok, so this is on my 07 silverado NBS ECSB, but the basics still apply.
the left front and rear door speakers work intermittently.
I pulled the speakers and the connections look perfect
I wiggled wires and no change.
My guess is the radio its self. I don't believe these go through an amp.
But, I do believe the chime and blinkers go through the amp correct?
If i'm not imagining things, sometime the chime and blinkers are not as loud
as normal. Not sure yet if its the same time as the speakers go out as I havent paid that much attention
Also, a few months ago, the radio quit spitting out the cd unless you hit the dash. Common issue?