I have a 2009 GMC Sierra SLE with factory radio and no nav. I noticed this a couple of days ago and again today, after I shut the engine off and radio off and opened the driver's door, I noticed what sounds like a faint electric motor running from behind or within the radio. Kind of sounds like a CD disc spinning, but there is no disc in the unit. The only way I could get that to stop was to pull the fuse for the radio.
Anyone else have this issue? I'm concerned about what it may be and if it will drain my battery if left to run.
Thanks.