Hello, just posting this to see what you guys think.

Ive got an 03 f150 reg cab short box and im having an issue with the running lights/parking lights/instrument lights not working. Everything else seems to work (brake,signal,headlight,fourway,radio,dome/map lights are working).

I started by checking all the fuses, all ones that did have power were hot on both side of the mini fuses. Under dash and hood.

I checked the wiring on the back of the truck, found a quick splice hooked up to the brown wire going to the light for the topper, took that off and soldered it up all nice, thought i had it in the bag...no dice, still same problem. Checked the rest of the wiring back there, looked good, took connections apart and put some dielectric grease in since i was there, still no progress. Front wiring is a lot to take in so ive come to you guys.

What i did tonight was run a hot wire from the battery right to brown wire on headlight switch connector and all running lights turned on and stayed on for 5 minutes no problem, the dash lights were not on, but maybe that was due to dimmer switch being on a different connector? ( both pugs disconnected from headlight switch at this time)

With my headlight switch connected and a voltmeter probed onto tan/white wire going into headlight switch there is 12 volts, turn to parking lights and the power vanishes to 0 volts on said tan/white wire. I did try another headlight switch from a salvage yard and same sad story. I put an ohmmeter on the switch and i think my headlight switch is okay (shows open circuit when switch is off and 0.5 ohm when parking lights position.

Im not sure what to make of this and hopefully ive written it on here clearly enough for you folks to understand and hopefully let me in on some insight/knowledge of your own,

Thanks, Lee