It seems like you are not getting consistent power to the radio, check all the fuses, relays and connections into the back of the radio. There are no radio codes to enter, check to see if it has 12 volts.
There are a few fusible links on this probably by the relay and that may be the problem if one of them burnt up or is partially burnt.
Monday, September 16th, 2013 AT 12:05 PM