For the wiring of the mirrors you will need some brown, green, white, black (factory colors) and red wires around 18 Ga. I am using the red wires to bring power to the defrost section of the mirrors. I will be using a 30 Amp relay and a switch to turn on/off the defrost section of the mirrors. I don't like Ford's idea of leaving on the defrost section of the mirror 100% of the time, so I will go with the relay/switch combo. Brown goes to both mirrors as this is your running lights. White, (passanger side)Green wires (driver's side) work the directional lights in each mirror. Black is the ground wire for both mirrors.
For the passanger side mirror wiring harness, I cut about 9' of red, black, white & brown wire. The white and brown wire will get the Ford OEM pins on them so they will fit into the factory connector in slots 4 for the turn signal light (white) & the brown (running light) in slot 7 on my truck.
When assambling the pins be very carefull to not bend them of de-form them in anyway. The Ford factory guys have a special tool that crimps their connectors so I had to overlap the flaps a little when I made up my connectors. I sodered my connectors also.
Push the red locking tab out of the Ford connector and the pins should go right in with a little effort. Push the pins from behind with a small screwdriver if it is a tight fit. Do not pull on the pins with a needle nose pliers as it doesn't take much pressure to FUBAR up these connectors.
When running the wiring thru the door to the cabin I completly pulled off the rubber conduit that fits in between the 2 pieces. I then ran a wire snake from the cabin thru the rubber conduit and into the door. Be very carefull when running the snake thru the rubber conduit to make sure you don't strip off some insulation to the wires allready in the conduit. Very important especially when pulling the wires thru to the cabin. The rubber conduit has an opening taped very tightly around the harness that is allready in there. It is easier to remove the rubber conduit and make sure you snake the wires thru with no problems, IMO. The entrance into the cabin has a slight dog leg in it too and the wire snake makes it super easy to get around this little problem area too, IMO.
I will be splicing the harness in later this week and will post those pics up also.