When we bought our 2004 Ford EXcursion Limited with 6.0L diesel, the fog lights didn't work. We checked bulbs, plugs, and replaced the headlight/parklight/foglight switch in the dash with a new one from Ford, and they still won't work.

Has anyone else had this problem? I think we are just going to take them off because it won't pass the state inspection with them not working.

 

You have the key in Run when you're testing right? That's the only key position that they operate with. Have you checked fuses?

 

This may sound wrong, but are you sure you are working the switch right?

I ask because a couple years back a friend bought an Expedition and was frustrated because she couldn't get the fog lights on. When I pulled the switch out and the lights came on, she was amazed. She didn't know how the switch worked.

When you replaced the switch, did you notice if any of the pins looked burnt?

 

Have the headlights been modified in any way by previous owners?

 

We tried all of that. Thanks! The Ford dealership said we should just take them off since its been like that since we bought it. They didn't even want to look for the problem.

 

Yes. They are blacked out projector style. I bought new clear ones to replace them, just haven't gotten around to changing them yet.

 

The switch is just like our F250, so that's not the problem.

None of the pins were burnt.

 

The relay for the Fog lights is a integral part of the CJB (Central junction Block or Fuse box)
If the coils of the relay are burned out, then you end up having to bypass it or buy a new CJB. A new CJB is major bucks.

First off, check to see if there is power coming out of the switch.

Pull the headlight switch and turn on the fog lights with the key in the run position.


Position number 5 on the back of the switch is a yellow wire. Check it with a meter and see if there is power..

If there is power, then you need to check the harness at the inline connection next to the engine. That inline connector may be bad, or the CJB Fog relay is bad.
If there is power at the in line connector, then the problem is in the wiring from there to the lights, or the lights themselves.

If there is power at the yellow wire, but not at the inline connector under the hood, then the relay is bad.

If you determine that the Fog lamp relay is bad, Then here is how to bypass it.


First, solder splice or use a crimp splice connector to attach a 16 ga txl insulated wire to the Yellow wire on the back of the light switch.
run that wire to one of the customer access wires under the dash and crimp them together.

In the engine compartment, get a waterproof inline battery holder to hold a blade fuse. Crimp a 5/16 inch ring terminal to it and attach it to the top post of the battery positive terminal.
Put a 15 amp fuse in it and crimp a 12 gauge TXL insulated wire to the other end. Run the power wire around the back of the compartment to the drivers side. Put it in a small split loom.
Cable tie it to the wiring harness as shown in the pictures. Get a bosch 5 pin relay with pigtails and a mounting tab and mount it to the side of the drivers inner fender.

crimp the power wire to the wire that corresponds to the number 30 pin of the relay

Put a serrated ring terminal on the 85 pin lead and bolt it to the body for ground. (see pictures)

Now find the customer access wire of the same color you used under the dash. Crimp on a 16 gauge wire and crimp this wire to the wire for the 86 pin of the relay.

Next, in the OEM fog light harness, anywhere before the connector next to the engine, you will find a Tan wire with a orange stripe.
Connect a 12 gauge wire between the tan/orange wire and the relay pigtail wire that corresponds to pin number 87.

Cover the wires in small loom, tape the ends, cable tie them to good locations along other harneses, and you are done.

That is how to bypass the fog light relay.

This method means that the fogs can come on with the high beams.
If you need to be able to have a hidden switch to have the fogs turn off when the highs are on, let me know.




Pictures are available at webshots in a album from where I added fog lights using the Ford fog light kit.

Webshots Rides offers thousands of the best car wallpapers.

Have fun!

 

Just for the heck of it, I drew a wiring diagram of the changes to make case your fog light relay is bad and you have to bypass it.

It also shows how to add a switch and relay to turn off the fogs with high beams during the bypass.


FOG LIGHT RELAYS AND BYPASS.pdf - PDF Archive

 

Thanks so much for the info! I will try it as soon as I can and I will let you know what I find.

Thanks!