2006 Ford Taurus Electrical

The logical place to start is by checking the fuses. Radios have a memory circuit for the clock and radio presets that is always tied into some other circuit that is always live, like the interior lights, horn, or cigarette lighter.

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.

PCM is the Engine Computer. That shouldn't be affected by a radio wire. Don't know what the other module is.

If you have no voltage on the radio's memory wire, and there's no blown fuses, this may be a dealer item. If Ford is pulling the same stunt GM dreamed up, replacement computers have to come from the dealer and have to be programmed to the car.