2006 Ford F-350 High Beam / Fog Lights Modification

One of the most annoying things about how cars are built, is some of the “Safety features” which really get in the way of how a vehicle operates. Particularly if you are off-road, or on wilderness back country roads where there is no light, or other vehicles around. One of these “safety features” is that the fog lamps automatically turn off when the high-beam lamps are turned on. This is because it could be too bright for oncoming traffic in the city.

Fog lamps are great in the snow and fog because they illuminate the road in front of you, instead of in the far distance. During snow and fog conditions distance lighting simply reflects on the snow or fog and obscures your vision. During normal summer operations, fog lights can provide a little bit extra illumination on dark rural roads.

If your vehicle is going to be in the back country, and/or on rural roads, then you may attempt this quick modification. Please note to check local laws before modifying the vehicle. It may also void any warranty you have with the vehicle. This how-to tutorial is provided for information purposes only, “as-is” with no warranty, expressed or implied. Basically if you damage your vehicle from reading this post, we advised you it was a bad idea. This modification is shown specifically with the 2006 Ford F350 Super Duty and has not been tested with any other year/make/model of vehicle. Use at your own risk.

The modification takes less than 20 minutes.

Tools needed:

ratchet
10mm socket
8mm socket
18”-24” of light gauge wire (we used 18ga)
Crimp ring terminal with about a 1/4” hole
Soldering iron / Solder OR crimp tubes
Wire cutters
Small heat shrink or electrical tape (optional)
Small flat head screwdriver (optional)

First of remove the fuse box cover panel under the steering wheel.
Next remover the (4) 10mm bolts holding in the fuse box

Gently pull the fuse box out of the dash a few centimetres (there’s a lot of wires behind there so it’s a little snug to pull out)
All the way on the right hand side of the fuse box there is a connection with a horseshoe shaped tab to pull and release the connection, do so

When the rear of the box with the mess of wires is visible, you will see something called a “horseshoe tab” there is only one on the box. You can stick your index finger in the hole, and pull gently. This will release the wiring harness from the fuse box.

Once you have pulled the horseshoe ring out, inspect the wires in the back. There should be a green wire with a black tracer (black line) along it. That is the wire which requires modification to override the fog lamp / high beam system in the 2006 Ford F-350 vehicle. You may have to carefully remove some of the factory wire wrapping off the wire cluster to access the wire. Be careful not to cut or damage the wire cluster or you could short circuit other electronics in the fuse panel.

Once you have pulled back the factory wire wrapping, and exposed the green wire with the black tracer (black line) you can now cut the wire, as shown in the picture below. Be sure you don’t cut the green wire with black tracer (black line) or you will not be able to attach a crimp tube or solder the wire.

You will now need to take the extra length of 18 – 24 gauge wire, strip both ends and put the crimp ring on one end. Make sure it’s a 1/4 inch hole on the crimp ring as we will be attaching it to a screw on the dashboard shortly.

Connect the newly created black wire to the green wire with black tracer (black line) on the clip side of the wire. This is the part of the wire that comes out of the fusebox, as shown in the picture. You can leave the other end loose, or tape it off if you desire. If you connect the wire to the wrong side, it will damage your vehicle – Do this at your own risk.

Apply a new layer of electrical tape to the wire harness, this will cover up the cut and exposed green wire, and give the vehicle a factory look for anytime someone goes under there in the future.

Now that everything has been modified, the difficult work is complete. Re-attach the wiring harness back into the fuse panel. Push on the black ring to lock it in place, as shown in the photo below.

To the right of the fuse panel, is an exposed metal frame of the dashboard. As you can see in the photograph, it has several 8mm screw terminals on it. Undo one of the screw terminals and connect the wire ring you created earlier to the screw terminal. This will act as a solid, connected, ground wire system for the fog lamp override.

After the new ground wire is connected, the project is complete.

Before re-assembling everything, start the vehicle and check the headlights. Start by turning the headlights on, and then high beams. Make sure they still operate. Then turn the low-beams on and pull the light switch to engage the fog lights. Then engage the high beams. The fog lights should now stay engaged, no matter the the headlight selection.

This post and photos were made December 15th, 2006 by Stump0331 and posted on the Powerstroke Diesel Forum