102.1 is the FM default setting. There is an AM default also, but I don't remember what it is. You really should test your battery as Sno White stated.

 

Us an amp meter on the battery to see if your starter is "starting" to crap out. It could be pulling a few hundred more amps then it should-causing a full draw to the starter with a momentary lapse of power to the rest of the vehicle, which also will kill a battery.

Don't you guys remember the old days when an amp meter (while testing a bad starter) would pin the RCH all the way to the right? (Family Forum-if you know what RCH is-laugh & keep it to yourself....)

 

Some meters had different color 'CH's' ..........

 

...

 

I have an '06 here. When I was having my problems {in this thread: https://www.chevyhhr.net/forums/audio-video-17/stereo-problems-36646/ } I had the radio out of the car for over a month. When I finally figured out it was the speakers and not the radio I put it back in everything was there the time, the station presets, even my equalizer settings, everything.

So I'm going with the onboard battery idea, at least for the Panasonic
6 disk changer unit in my buggy.

 

I just opened up the OEM radio from our 06 (we changed it out for a later radio w/USB). There's no battery.