I decided my lights were too dim. I looked into the RJM harness, which looked like a GREAT product, but I couldn't afford it at the time. So I built my own. I had everything I needed except the headlight plugs which I got at Oreilly's for $10.
It uses the same coloring (almost) as the original harness, red for low beams, green for high beams, each of which have their own fuse. Ground is orange. It uses standard Ford relays so replacements will be plentiful. It is all 12 gauge wire so current won't be too limited. There is a run of ~14 gauge that goes into each of the headlight connectors but they are only ~4 inches long.
No hacking of the factory wiring was done, so the harness can be removed like it was never even there.
The parts list includes:
Relays x2
12 gauge wire in 3 different colors
2 30 amp fuses
Heatshrink tubing
Solder
Varoius wire connectors
Zipties
1/2" wire loom
2 headlight connectors
Here is how the circuit is wired: