Trying to figure this out. Did a heater core on this 01 expedition Eddie Bauer edition with a 4.6l. Guy swears his low beams were working but on the way home the day I started the job it was midday so no lights were needed as was the case Sunday, the following day as the truck wasnt driven anywhere. Monday morning, it was light out on the way to work so no lights needed again. Did not completely pull the dash simply loosened the bolts and moved the passenger side around far enough to make due. I have checked all fuses inside at the driver panel and all are good as is the case under the hood. Swapped both the main switch and multifunction switch with new units to no avail. High beams function both in the on position and flash to pass. Low and fog never come on. New bulbs in headlights. With a power probe I can turn fogs on but not via the switch. Fog indicator does not illuminate. Has anyone run into this? Not sure where the low or high beam relays are as I can't find a good labeled diagram . Any help is appreciated .

 

With or without Autolamps? DRLs? There are different circuit diagrams for each permutation.

 

Certainly apologize for leaving out such pertinent information. Vehicle is equipped with auto headlamps and drl.

 

Check for 12 volt power at both sides of pin 9 at connector C253 when the headlights are turned on. Then check for 12 volt power at both sides of pin 4 as you flip the dimmer from hi to low and back. Pin 4 should have power in the low position. Pin 9 supplies power to the dimmer low side and pin 4 is the output from the switch to the low beams. It's possible that in not removing the dash entirely you could've tugged the wires and broke one of them.

See the attached PDF for the pin-out and location of C253.

 

There might be an easier thing to check instead of first jumping into connector C253.

Looking closer at the diagrams, there is, regardless of whether the Expy is equipped with DRLs or not, there is a connector (C2003) over on the RIGHT side of the instrument panel that the low beam circuit must pass through. For a non-DRL truck, the connection is simply jumpered. With DRLs, there's a relay box up in there behind the glovebox that has to be in the circuit or neither the low beams or fogs will work. Note: This portion is immediately downstream from the circuit that alloro highlighted. I'm focusing on this part because the odds are high that you had to disconnect the connector to the DRL relay box in order to pull out that side of the dash.

Also note: If the low-beams don't work, neither will the fogs.

Good luck!

 

I thank you guys for the great info. Started off by popping the upper dash cover off to check for the connection and surely enough that was the problem. Great info. Hopefully this can help someone in the future.

 

Good call, I forgot about that jumper.