[PumpItUp]

There's your problem right there.. You paid it off!!!! Should have traded in for something else. ..kidding(sort of) Weather related door actuator problem.. hmmm. Sounds as though humidity isn't the factor and assumed maybe it was a relay acting up in moist conditions but, no?? You may have to pull off the panel on the door to access the motor and be able to view what's happening or not happening. (look up "actuator motor" problems bydoing a "search" at top left of this page) and check the actuator and what it is doing and the sound of plastic/neoprene gears not meshing (first sign) Then if not that, then try checking all connections and taughtness maybe when it heats up outside there is some stretching in the wiring harness connectors from the buttons on the door to the motor etc. If it's the actuator motor acting up by trying the key fob and the door panel relay knob.. then the motor should be replaced could be just a dead spot in it as well. I have taken out and replaced FOUR!! of these &$%@$# motors passenger door twice /drivers door and rear hatch .. By doing a search I had found a web page with info on how to get at it.. + wreckers costs are way way better then Fords You'll see!