The way the circiut is set up from the factory, the fog light relay is grounded thru the high beams (not enought current to light the high beams, but the circuit is completed so the fog lights work). When you turn on the high beams, voltage is back fed thru the relay eliminating any voltage differential across the coil (in the relay) and deenergising the coil and turning off the fog lights. When you bend tab #1 and connect it to ground you are bypassing the high beam circuit and now your fogs will work in low and high.


Additional mod

Instead of grounding the #1 tab on the fog light relay,feed it to the coil of a second relay (for a set of aftermarket lights) and then to ground, and now your factory fog light switch will control both sets at the same time and still work with low or high beams

 

Hi guys,
I've did this to my '05 F150 a while ago and it works great!! Was wondering if there is any way to do this to an '01 F250??
Thanks

 

I have an 03 F150 Supercrew there is no fuse panel under the passenger side. The only fuse panel is under the hood. Will this same procedure work?

 

Great post!!! Only took a few minutes to complete.

 

Still working flawlessly to this day. Works GREAT on back roads when nobody else is around.. Turns night into day without adding PIAA or any other auxiliary light.

 

Amen to that!

 

I noticed that now my running lights won't wok if I just want to run them. Is this common? I don't really care a whole lot, because I would rarely just use the running lights.

 

I have full function of my headlights, running light and fogs.

I can turn on just my running lights if I want. I think you might have messed up bud.