Here's the diagram for your 2005 superduty. If fuse 17 in the underdash fuse box is good, you will need to find the security module and see if you have power on the tan/white going in, and on the brown going out to the lights.

 

Sorry to hash up an old thread, but I have a 2004 f250 super duty 6.no. My tail, clearance, dash, fog, parking lights will not come on when I start the truck. However, while warming up, they will come on. Sometimes after driving a few miles. Is there a relay somewhere that I may be missing? All fuses are good, stock radio, everything is stock except the work done to the engine. I'm kinda lost on this one.

 

As you can see in the diagram in the post above, there is a relay made into the vehicle security module. That is a 2005 but yours is most likely the same.

 

I will check it as soon as the sun comes up. Hopefully it's the same.

 

The relay in the VSM is only in play when the light switch is in AUTO or when the VSM locks or unlocks the system and flashes the lights.

If one turns the switch to either PARK or HEADLIGHT switch, the VSM relay is not in the circuit, it is bypassed.

Focus on F17 delivering power and the main headlight switch (left side of the diagram above).

 

Thanks for bailing me out again.

 

Bringing this back to life. Our truck started to do this exact thing. No running, tail, or clearance lights for a few minutes after starting. Replaced the headlight switch, but still happens.
Don’t think it is a fuse because we get power eventually to the bulbs. Relay? Which one, where is it located in a 2004 F350?

How did you resolve this problem?
Thanks

 

My fuse panel was burnt and melted behind the parking lights fuse. Put a new panel in and problem never came back.

 

We got it figured out. Because the lights out was only occurring immediately after startup when cold, they would suddenly turn on after a bit of warm up, I didn’t suspect a fuse.
Replaced the switch, no change. Started hunting for broken wires and noticed a fuse looked a bit odd, kind of deformed, melted maybe?
Pulled it out, swapped in a new one and we have lights again. Not sure how I had an intermittent fuse, but I did.
Check them first.

 

What is the location of the security module? Is it in the fuse panel in the dash or undr the hood? Sorry 03 f250 6.0L
thanks

 

I found some info saying it's behind the radio toward the right.

 

thank you Franklin2.

 

 

Do the front parking lights work correctly or not?

 

I am assuming the roof marker lights are factory? If we assume that, I was looking in the diagrams, the roof markers are fed from a splice s215 right after the headlight switch.

There is a tan/white that feeds power from the fuse box to the headlight switch just for the marker lights. We know that is good since your roof markers are working. Coming out of the headlight switch is a brown wire that feeds all the markers in the whole truck.. The first thing this brown wire hits is splice s215, which feeds the marker lights which are working. The brown continues on to the underdash fuse box. In the fuse box it splits out into the trailer tow parking lamp relay, and also splits into two brown wires, one feeding front parking lights in the fenders and grille, and the other brown feeding the rear parking lights.

I do not know where this splice s215 is located, but that would be the place to find. Apparently you are good till you hit that point, and after the splice, power is not making it to the fuse box and the tow relay area. If the front lights are working like projectsho89 was asking, then we know the wire from the splice to the fuse box is good, and where it splits in the fuse box can be a problem or afterward since in the fuse box tow area is where it splits front and rear.