First look at the original wiring here:
http://fullsizebronco.com/forum/showthread.php?s=&threadid=9397
NOTES
This wires the switches so they both work without the key in the ingition.
It also takes the load off the dash switch. Now the dash switch only suplys 1/8 amp for a relay
For this to work well you need a GOOD ground near the relays.
You need to route a 10gauge or larger wire to the relays in the back.
I mounted my new relays in the back inner quarter panel above the wheel arch.
I recomend replacing the power wire for the tailgate switch; wire it to the same circuit as the relays.
Ok you're responsible for getting a Battery HOT wire threw the firewall. I'm anal about wires and fuses so any help from me will be very complicated for this simple electrical work. It needs to be BIG.
INTRUCTIONS
From that Battery HOT run a 18 gauge wire to the Lite Blue / Black wire on the dash switch. This will make the switch work without the key.
Also cut the Pink/Green and Pink/Blue wires. Splice 18 gauge wires to the switch and route them to the drivers kick panel.
Run a 10 Gauge or larger wire from Battery HOT to the drivers kick panel with the 2 18Ga wires from the switch.
Remove the Door sill cover and route all 3 wires along the drivers rocker panel past the seat belt tensoner trim panel and up to the drivers inner quarter panel above the wheel arch.
Drill a hole threw the inner quater panel and route 3 10ga wires down to below the drivers tail light. I prefer a Red wire Blue Wire and Green Wire. But if you get all Purple wire, I don't care, just keep them from getting mixed up!
Behind the Drivers tail light are the tailgate plugs. I recomend removing any questionable wiring, but your wiring skill may stop that from hapening.
Splice the Red 10Ga wire to the Black/White wire
Splice the Blue 10Ga wire to the Pink/Blue wire
Splice the Green 10Ga wire to the Pink/Green wire
Now at the inner quarter panel mount 2 relays. try to sand down the metal at one of the screw holes as you will use that for a new ground. This Ground has to be GOOD!
Wire up the relays as the diagram above shows. When you splice all the power wires togeather make sure it's not a half ass job. Same for the grounds. The better your power and ground the faster the window will move and the less it will bind up under load.