radio issue, please help
 

My radio will stop working once in a while when it is cold out. I have it narrowed down a little, it only happens when it is cold out, it will stop working no display no sound no bluetooth but the buttons will remain lit and the memory will keep. Then if I pull out fuse #42 (maybe its 41 can't remember) and reinsert it the radio will begin working again. I read somewhere that this may be because the radio is sensing a low voltage and going into sleep mode to reserve battery life. I changed to a agm battery last month hoping that it would fix my issue but no luck. My wife does make short trips daily which I know drains on the battery but is there any way to stop this radio issue from happening? Is this normal is my radio too sensitive to voltage changes?

I have not heard of a radio being this sensitive. You may check your alternator voltage with a multimeter on the battery running. An analog one is best to see if the voltage is fluctuating from the alternator as well. If the needle is bouncing all over you likely have an issue. You can always remove the batter and alternator and have them tested at your local auto parts store.

I tried testing the voltage on battery and alternator like you suggested but everything was good. I took the vehicle back to dealer and they said that my radio had an internal failure and needed to be replaced. I talked to them knowing that the radio is not covered under the CPO warranty and they were nice enough to take care of it for me anyway so I got a new radio.

Very good, luckily eBay is usually good for finding used components for our aging cars. Its the cycle. I just replaced an $1800 abs pump assembly in my E39 and 2 wheel speed sensors for $150. That rocks!