Well, for the second time I just looked through the wiring for the power fold mirrors and don't see a relay anywhere except in the heater circuits. The power fold motor in each mirror is controlled through the Driver's Seat Module on circuits CPM-39 and CPM-04 and runs through connectors C341C, C219 (on some models,) and C521 at the mirror.

The DSM gets the fold signal directly from the power mirror switch through circuit CPM22. It goes through connectors C527, C219 (on some models,) C300, and C341C at the DSM.

If you find out where that relay is, make sure you come back and update this thread and I will show Ford so they can update their wiring diagrams.