Here is a write up from one of our members STUMPY
Stumbled across this mod before the thanksgiving holiday and did it soon as i got a chance. It really helps when driving down country roads, and lights things up a little without having to buy additional fog lights.
What this mod does is allows the factory fog lights to remain on when the high beams are activated. Normally when the fog lights are on and the high beams are turned on the fog lights will turn off.
This is done by providing a ground to the fog lamp relay so that it will remain on when the high beams are activated.
This can be done on:
12/01 and Later builds of 2002 Model Year
2003 Model Year with 7.3 liter Powerstroke
2003 Model Year with 6.0 liter Powerstroke
2004 Model Year
2005 Model Year
This CAN NOT be done on:
SOME 11/01 and Earlier builds of 2002 Model Year
2001, 2000, 1999, etc Model Year
Candian Vehicles / Vehicles with "DRL" Daytime Running Lights
Non-Superduties, e.g. F-150
if the wire in slot 13 and NOT LG/Bl it cant be done
The mod took about 20 minutes and even a beginner at mods could do this with ease.
I apologize for some of the fuzzy pics but I think you can get the point.
18”-24” of light gauge wire (I used 18ga)
Crimp ring terminal with about a 1/4” hole
Small heat shrink
Small flat head screwdriver
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 inches (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
On the side that the wires come in to the connection as you look at it with the horseshoe tab up, the top left wire is in slot 13, which it is labeled; this will be a green wire with a black tracer.
Cut this wire about 4”-6” inches away from the connection.
You can now tape back the end that comes from under the dash (DO NOT TAPE BACK THE END THAT GOES INTO THE CONNECTOR)
Connect the crimp ring to the 18” -24” piece of wire.
Solder the other end of that wire to the green and black wire that is coming out of the connector, heat shrink that wire connection
Tape it all back up and reconnect the horseshoe connection
Under the dash all the way to the right on the dash bracing there are 2 ground connections already in place for the ring terminal to bolt in with the 8mm
Bolt the fuse box back in place and reinstall the fuse box cover panel
All head lamp and fog lamps will function the same with the exception of the fog lamps will stay on while the high beams are on.
I did this on a 2004 Excursion and I am not sure what other year models this will work on, but like I said earlier very easy mod and takes no time, for most of us it wont cost anything, since most of this stuff is probably already laying around the shop.