Then I'd start by testing for supply voltages in the radio's electrical connector. You'll need the service manual for that. Unfortunately Ford lost too much money in the '90s from the three or four radios I repaired every year, so now they won''t sell us radio service manuals any longer. Doesn't help you. Doesn't help me. But it makes Ford's repair centers lots of money.
You have to have 12 volts on at least one wire when the ignition switch is turned off. There is likely not a second 12 volt wire with the ignition switch on because due to a lack of common sense, most manufacturers are turning the radios on now with a computer signal.
I don't think you have a radio problem, or a problem with the signal that turns it on. You have lock problems too that have nothing to do with the radio, so begin the diagnosis with the assumption that all of the symptoms have a single, common cause.
Sunday, July 20th, 2014 AT 9:08 PM