Anyone have a source for a headlight wiring diagram for a 2002 F250 with DRL? I need to figure out why my headlights only work when they feel like it.

The DRL work, though sometimes I wish they didn't (truck came from Canada). Flash to pass and all the other lights and functions work. But intermittently, the low beam and high beam function quit working. I drove home at 11:00PM last night with the markers and DRL only.

With the wiring diagram I have, I am leaning towards the switch or a loose wire behind it. This diagram doesn't have the DRL, and the fuse numbers don't match the manual, so I don't think I have the right one.

 

Go to autozone and register(it's pretty painless with no side affects that I have noticed). Then plug in your truck and then click on "vehicle repair guides" Then click on wiring diagrams. They have really good factory type diagrams for your year truck.

 

Found it. This is a great resource. Thanks.

 

Well, the switch seems to be working. I am going into the column to check the multifunction switch tonight. I have a bad feeling about this one . . .

 

It probably is the switch. Here are the DRL diagrams.

 

I found a loose wire in the column. I think it is the wire for the door open/key in ignition chime. When I touched it to a ground, I could watch the lights go out. Right now I have it outside the column and taped off. The only thing that doesn't work now is the chime.

I am no electrician, but I'll be damned if I can see on the schematics how those two circuits interract. When it was grounding out, it would interrupt the headlight power from the turn signal switch to the fuses. Finding it was pure luck.

 

At least you got it working. You can bypass the DRL by using the above diagrams. You connect the red/yellow to the red/black on the DRL module, (disconnect from DRL), and the DRL is bypassed.

 

I thought pulling the fuse would disable the DRL? That's my next project.

 

That's right, fuse #6.

 

My daylight lights sometimes shut off at night, I have to switch on headlights to see, then sometime later they start working again. What controls them? I have a rubber cup over the light sensor so their always on, maybe these are "auto" lights, not DRL? Anyway, where to look for an intermittent open or short in that circuit?

 

When the lights in question are on, see if the taillights are working. Taillights do not work with DRL's. So then you can figure out which mode it's in. I certainly hope you do not rely on the DRL's to see, that means the your taillights are not on and it will be hard for people behind you to see you. I see this all the time though.

 

I don't have DRL, I have "auto" on my light switch.. it has a sensor on the dash, when its dark the lights come on, daylight their off... but, they keep turning off when its pitch black outside..

 

You need to run them on regular "on" or manual on headlights. If the problem goes away, it's going to be the sensor or something wrong in the vehicle security module. The sensor tells the VSM if there is any ambient light, and there are a bunch of relays and logic in the VSM that turns the lights on and off. If you put the headlight switch in manual on, it bypasses these two components, but does not bypass the headlight switch itself, and does not bypass the dimmer switch in the column and all the wiring out to the lights.

 

If it turns out to be a bad sensor or controller, where is it located?8

 

The sunload sensor is located in the dash panel. The Vehicle Security Module is located under the dash way up high over the transmission hump, a little toward the glove box.