Late Model Ford Truck Tech Tips

Highbeams and Foglights Simultaneously...
(an easy and inexpensive how-to)
Contributed by Terry Thompson
(Webmaster note: The Tech article So you want to add some electrical accessories to your new truck... may be a good primer to read before attempting this modification, especially if you are unfamiliar with your vehicle's electrical system)

I was able to accomplish having highbeams and foglights on at the same time using a lighting relay and a KC Hi-brutes kit.

The instructions included in the kit, however, were specifically for GM pickup trucks, to go from a two to four headlight system.

If you are like many truck people, you may be familiar with the lighting system on those trucks; the dims lights are on alone and when you put on your brights the dims shut off - a two on/two off system.

You can accomplish the same result with any relay, wire and connectors you buy at an auto parts store.

To make it even easier, Painless Wiring has these materials similarly packaged as a kit.

The steps in accomplishing this result are:

  1. Remove the headlight by removing the two quick pins and lifting it out (this make the process much easier)
  2. Locate the hot lead for the dim headlight.
  3. Hook it up to the power side of the relay's (30 amp) red wire.
  4. Hook the ground to the frame (bare metal) black wire.
  5. Connect the fog lights up to the out power side of relay's green wire.
  6. Connect the dim side using the white wire.

You'll have a total of four wires to hook up.

The installation should take about an hour and the cost of the pre-made kits came in at around $20.00.

Under the new scenario, your fogs will come on even if you do not have them on when you put on the brights. To avoid this, use install an additional power switch to turn the system on and off.

Additionally, your factory fog indicator light will also be over ridden. To avoid this from happening I also used a extra toggle switch to turn the system on and off when desired.

Have fun!