My Tip/Trick To Simplify Wiring Aftermarket Fog/Driving Lights to OEM Harness
For those looking to take advantage of the stock wire harness and switch for the foglights because you're replacing the OEM foglights or found out that you have the harness tucked away even though you don't have the lights, an inexpensive 9006 pigtail may simplify installing aftermarket fog/driving lights. This will not compromise the OEM harness or put the extra load on it if your new lights are higher wattage.
By way of brief background, I installed 2 sets of PIAA lights-1 fog, 1 driving, each bulb is 55w- on a heavy duty bumper. Since I removed the OEM foglights, I hoped to splice the new fogs directly to the OEM harness and use the OEM switch, but the OEM foglights were 37w each (pic #1). The new driving lights were wired separately to supplied switch.
PIAA said if the the OEM harness was protected by a minimum 10amp fuse, I should be OK, 15amp no problem. Ford service tech wouldn't confirm or deny if OEM harness could handle the extra load, but did say splice in at own risk- any damage would not be covered under warranty. A few forum members said use a harness and relay. So I played it safe and compromised- here's how.
Purchase a 9006 male pigtail from theretrofitsource.com for $7.50 total (pic #2).
Lay out wire harness. Determine where you want to run the wires and secure the relay(s). I secured the relays next to the battery, adjacent to the windshield wiper fluid container (pic #3) and ran the wires down to the lights behind the washer fluid container, along the fender (pic#4).
I ran the wires for the passenger side lights thru a cross member using a wire fish so they are out of the way and protected (pic #5).
Splice the 9006 pigtail to the the new light harness switch wires from the relay (pic#6) and plug the 9006 pigtail connector to the OEM foglight connector. I used marine grade butt connectors for the splice.
Ensure the lights are plugged in and connections are good. Connect + and - wires to the power source per the manufacturer's directions. PIAA recommended connecting to the battery directly. Once done, turn on the truck, and the new lights will operate directly off of the factory switch just like the old OEM foglights. Hope this tip is helpful to someone.
Last edited by Driftboater; 04-14-2014 at 12:32 PM.