2006 F150 SuperCrew
driver side lowbeam has suddenly stopped coming on (DRL or normal operations)
Have change bulb
Checked both lowbeam fuses (#23 and 25) and even switched them
Still won't come on
Any suggestions before I have to resort to going to a dealer?

 

It wouldn't be the fuse
Have a look at the socket where the bulb plugs in

 

have you checked to see if you have power to the socket?
do u no 100% that the bulb works? (wouldnt b the first time a new one was shot too.)
if no power at socket, check power at the fuse, though i would suggest being careful about this.
if powers good there then mx4matt nailed it on the socket.

you didnt happen to put it higher wattage bulbs did u? check the contacts on the socket too.

 

You could swap the bulbs too as a check to see if the new one is bad.

If still no go, you clearly have a break in the electrical supply somewhere.

According to the wiring diagram I have in my Haynes manual, there's a single red/black supply wire to the fuse box for fuzes 23 and 25. This means if one of the fuzes gets voltage, the other does too. Then there is a blue/white wire that runs from the fuze box to supply the left headlight low beam. The right low beam is green/orange.

So, since one of the headlights works, I'd suspect a problem in the blue/white wiring. Perhaps it's loose/broken at the headlight connector -or- you could have corrosion in the connector for the low beam.

Good luck on this!!

- Jack

 

Based on the advise provided, I decided to have another look at the headlamp assembly. Sure enough discovered a nick in the wiring leading to the main headlamp plug. Once I peeled back the tape it was the blue/white wire that was completely cut.
Not sure if this was the result of the repair work from a large bang up last summer that wasn't found or fixed right or if I have critters that like to chew on the wiring.
Just to be safe- the dog is going to have sleep outside from now on.
Thanks everyone.

 

We've had problems like that here in Tucson with packrats. They think wires are great to gnaw on. If we can't keep our vehicles inside, one approach is to leave the hood up - they don't seem to find the engine compartment as "homey" then.

Another, far better approach, is to put a light in the engine compartment and have it on overnight. I helped a friend install an LED light for just that purpose that is hotwired to the battery. A sort of "set and forget" solution. You can buy these things with 1156 bases now and they draw so little battery power that they don't drain it.

(You can see I'm trying to get your dog back inside where it's warm again )

- Jack