As yet another part of my continuing 100K mini rehab/restore, I added factory fog lights to my '99 XL. This mod consists of adding the fog lights, a fog light valance and headlight switch, and the wiring to run it all.




Approximate mod cost:

• Headlight switch w/ fogs ... $25 (used, ebay)
• Valance w/ fogs ... $50-$300 (depending condition/quality)
• Fog lights/brackets ... $100 (Depo, new)
• Wiring, 12V relay, H10 connectors, fuses/holders, bolts/extruded U-nuts, etc. ... $30

Notes on this write-up:

• The wiring at the headlight switch described below is correct for '97-'99 F-150/Expy, but of course the fog lights themselves differ between '97/'98 and '99.
• The wiring at the headlight switch described below is probably not correct for '00-'03 F-150's. If anyone knows the correct wiring at the switch for these years, please let me know and I'll add it to the write up.
• Following the steps below will result in stock-operating fog lights (on w/low beam, off w/ high beam). If you want the option of fogs on at other times, follow my write up on modifying the switch/wiring.
  https://www.f150online.com/forums/ar...witch-mod.html

Switch

Add a factory fog headlight switch.

You'll need a factory headlight switch w/ fogs for this mod. You MUST get a switch for a '97-'99. The switches from a '00-'03 will not work. While the '97-'99 and '00-'03 switches look very similiar on the front, they mount differently and have different wiring connectors. The ***** on all '97-'99 switches will pull out (like you would to turn on the fogs), but only the switches that say "pull for fog" and have the fog icon are wired for fog lights.

On a '97-'99, the switch is removed by turning the **** to the ON position and pulling it out, using a small pin to release the ****, removing the ****, rotating it 1/2 turn and pushing it back on the shaft, turning the **** back to the OFF position, and then back again to the ON position to release the switch.

I'd love to have a beer w/ the engineer who designed that removal system. He either got a huge promotion for his cleverness, or was fired as soon as the execs realized what he had done.





Wiring


A note on wiring ...
Ford goes to great expense to provide a reliable and safe wiring system for our trucks (never mind the cruise control problem). In my opinion, you want to do the same when you add wiring to their system. Not doing so will likely result in problems ranging from a failure of the system you added (best case), to an electrical fire burning up your truck (worst case). Do your wiring mods right the first time and you'll never have to visit them again.


As always, remove the neg cable at the battery, prior to messing w/ any wiring (Pic so you won't forget).




Wiring at the Switch:

My XL had wiring for fog lights from the headlight switch to a large connector on the firewall (connector # C160), but no wiring from the firewall to the under-hood fuse box, or from the fusebox to the corners of the bumper for the fog lights. Rather than add pins/wiring to connector C160 and the fusebox, I added new wiring (w/ relay) from the switch to the fog lights.

With the switch out, you'll see three connectors ... a large black (C246), a large gray (C245), and a small gray (C244).

Splice a wire (long enough to run from the switch, through the firewall, to the under-hood fusebox, approx 6') onto one of the white w/ black stripe wires coming from the small gray connector. This wire will be connected to pin 86 on your fog light relay.

Splice a second wire (preferably a different color) onto the yellow wire coming out of the large black connector. This wire will be connected to pin 85 on your fog light relay.




Bundle these two wires in a loom of some sort, and run them through the firewall to the inner fender next to the under-hood fuse box. I used an existing rubber grommet near the brake booster to get through the firewall.




Notes on wiring at the switch:

• The wires you add can be small (20Ga), as there is very little load on them
• Install a 2A fuse in the new wires as close to the splice as possible ... this will prevent any problems in your new system from damaging your existing system
• Make your splices in a manner which is reliable and won't damage the existing wiring (I carefully stripped a small portion of the insulation from the existing wire and soldered the new wire there, insulating it w/ elec tape and liquid elec tape)

 

Wiring the Relay:

Mount a 12V, 30A automotive Bosch-type relay to the inner fender near the under-hood fusebox.

Get power to the relay by running a 14 ga wire from the power input terminal on the end of the under-hood fusebox (remove the fusebox cover to expose the terminal), to pin 30 on the relay. Put a fuse holder w/ 15A fuse on this wire, as close to the fusebox terminal as practical.

Connect the wire you spliced to the white w/ black stripe wire at the switch to pin 86 on the relay.

Connect the wire you spliced to the yellow wire at the switch to pin 85 on the relay.

Because I also have Reverse and Grill lights, I added a small fuse box and a relay bank (I still need to add the relay for the grill lights). Power runs from the under-hood fuse box to the small fuse box, and from there to the relays.




Wiring the Lights:

Run a 14 Ga wire from pin 87 on the relay to the fog lights, and run a 14 Ga wire from the foglights to ground.




I made up a quick harness for powering/grounding the lights as follows:

I ran the power wire from the relay, following the factory light harness, to near the back of the left headlight. At this location, I spliced a wire (14 Ga) onto it to drop down to the left fog light. I then continued following the factory light harness across the upper radiator support to near the back of the right headlight, where I dropped it down to the right fog light.

A second wire (for ground) was run from the left fog light, following the power wire, over to the right fog light. Near the back of the right headlight, I spliced a wire onto the ground wire and ran it to a green ground screw located behind the right headlight (remove the right headlight to access this ground screw).


Splice on a H10 connector to the power and ground wires at each fog light.

Put all the wires in some sort of loom, and zip tie them securely to existing looms, etc.

I added wires for my grill lights into the same harness, as well as connecting the grill light grounds to the ground wire for the fog lights.






Fog Lights

Installing the Fog Lights:

Remove the 12 8mm bolts holding the valance to the bottom of the bumper and remove the valance. You'll also have to remove 3 Cristmas tree plugs holding the rubber air deflector to the valance in order to remove the valance.

Attach the U-nuts (3 for each light) to the holes on the bottom of the bumper. Bolt the fog light bracket (w/ fog light) to the bumper, snugging up the bolts but leaving them loose enough to adjust the bracket on the bumper.

On my 4X4, I used 6 of the bolts/U-nuts from my original valance which held on the lower part of the 4X4 two-part valance, to mount the fog lights. On a 4x2, steal 6 of the U-nuts from your original valance, and get 6 bolts from the hardware store (M6, I think) to mount the fog lights.



Mount your new fog valance, using the 12 bolts from your original valance. Don't forget the 3 Christmas tree plugs to mount the rubber air deflector to the valance.

Adjust the fog light bracket, so the fog light properly fills the hole in the valance. Tighten the 6 fog light bracket bolts.

Plug the fog light connectors into the back of the fog lights.


Fog Light Debris Shield:

I didn't like how exposed the back of the fog lights were to debris thrown up by the front tires, so I fabricated some shields to cover the back of the fog lights.

I used some cardboard to come up w/ the shape I wanted. I then cut the shape from a piece of aluminium highway sign panel, and bent them in a vise. The mounting holes in the fog light brackets were threaded to make installation/removal easy (the shields must be removed to change the fog light bulbs). A quick coat of flat black paint helps them hide in the wheel well.






Finished Product ...




Have a beer and enjoy your new factory-looking fog light installation (not at the same time, please)

 

Looks good, and iknow ur not done posting this up yet, but what your saying with the 97-99s, even tho im prewired and my switch pulls out, the fog option wont work? Until i get the proper fog switch?

 

Never mind ....

 

Correct ... the non-fog switch will pull out (it's part of the switch removal system), but it's not wired for fogs.

 

ahh ok.. so just the new switch should work for me? since i'm assuming all the plugs n such should be there.

 

nice write up

 

Thanks ...

 

Good job on the write-up! It's nice to see people contribute things like this to the forum.

Your truck looks really good. Nice and clean.

 

Excellent write-up and that is the sexiest aftermarket wiring run I've ever seen.

-Alex

 

Fairlaner, really nice work! My 2003 is an XL, and I want to add some XLT options, so your post is hugely appreciated. Thx. I think your write-ups are the best I have ever seen on any discussion board and on any topic. Amazing.

 

I have an 03 XL that got smashed in the front. While i was removing the damage I noticed several wire plugs on the radiator support, Could my truck be prewired for the fogs? Because I figure since Ive have to replace it I may as well upgrade.

 

Thanks for the kind comments. I've gotten a lot from this site ... just trying to give a little back.

 

lookin great!

 

Yeah that truck looks awesome, nice write-up