I have a 2003e f350. The park lights on my truck aren't working. The brake lights, turn signal, hazards, healights, fog lights, mirror turn signals, and dash lights all work, but none of the park lights will work ( the front, the rear, or mirror lights) will not work. I have checked the fuses but didn't find any blown. Does anyone have any ideas.

 

If the fuses are good, and all the marker/parking lights are out...I'd check the switch. This is assuming that all the bulbs didn't go at one time (they were installed on the same day)

 

IF you are 100% sure that you don't have a blown fuse, then I'd almost suspect the switch itself.......

 

That's what I was thinking too but the interior lights come on in all positions as they should. Wouldn't the interior lights run on the same circuit from the switch and then branch off?

 

Check the wiring on the back of the switch. When you say interior lights...are you talking about the dash lights or the dome lights? The later are on a different part of the switch than the marker lights.

 

The dash lights come on when I turn the switch to the different positions.

 

Thinking out loud here...either all the running light bulbs went at once (not likely) or there's a bad relay/broke wire. I don't have a wiring diagram...sorry I couldn't be of more help than that.

 

Yeah I need to look at a wiring diagram. I was thinking along the same lines as you. I appreciate the help