Volvo: radio settings lost when car turned off, fuse box, starter motors

Question
The radio works fine and allows setting of stations.  However, sometimes upon starting the car, the stations selected are lost.  All channels default to same station.  resetting them results in stations being saved until another time when lost.  It appears as if power to radio is lost when car turned off.

Is there a particular power supply or circuit that may be suspect?

Any suggestions would be appreciated.

john  

Answer
There is a 12 volt constant line running to the back of the radio to keep the memory when the car is turned off.  My guess is that you've developed a problem with that line, either a loose connection, or a ground problem between the radio and the fuse box.  I would also check your battery.  If when you start the car, the voltage drops well below 12, then the radio will lose its memory even if that line is good.  Older batteries or starter motors that are going bad will produce greater voltage fluxuations.  Good luck!