I'm trouble shooting a 1997 F150 with my grandson. The radio power does not come on. There is 12 volts at the constant on wire, but the 12 volt accessory power does not come on. We've checked a 15amp fuse under the hood and a 5amp fuse in the cab, but I'm not sure these are the right ones. The truck has sat unused for a long period. My fear is a bad contact at the ignition switch on the steering column. I don't have a schematic. I'd like confirmation of what fuses and relays (if any) to check. If fuses and relays are really OK, where and how should I look for the bad connection or contact? I don't want to just wire power to the radio's 12 volt accessory input through a new switch. That's my last resort.

Can anybody help?

 

Is this radio factory with factory wiring?

EDIT: This might be an Expedition only thing, but check if you have fuse #3 in this small under hood fuse panel. If you do, make sure it's good.

 

There was only one fuse in that box on his truck, but it was the right one. Replacing that fuse restored radio power. Many thanks.