Look for a blown memory fuse. On many imports, that fuse is plugged in on the back of the radio. On other cars, it is usually tied in with some other circuit that is always live. Typical circuits used include interior lights, horn, brake lights, or cigarette lighter. Fuses often blow from current surges when the battery is disconnected and reconnected or when jump-starting a dead battery.
Wednesday, October 26th, 2011 AT 7:02 PM