Alright guys ive got good one for you all to help me figure out. I purchased a 2007 F150 XLT 4x4 a few months back. Im from the south so finding a relaible work truck with under 200k miles and affordable is quite the feat. Previous owner made me aware of a few small issues that werent concerning and all have been resolved. However, and this is a big however, this one electrical issue specifically with the headlights is about to drive me crazy. Ive done everything I can possibly think of with no results. I will explain in as much detail as possible now and cross my fingers someone else has ran into this and found a solution.

Ill start by saying that all of the bulbs related to the headlights, tailights, dashlights or foglights do work and are not blown. When you set the headlight switch to auto on/off the headlights and taillights work as they should on both high and low functions but the dashlights do not Illluminate.

When setting mode to parking lights only dashlights and all work as should but if you try and shift out of park trunk immediately dies.

When turning headlight to manual mode low beam, dashlights work as they should and you can shift out of park without the motor dying. However, there are no running lights on in the rear... only brake lights and if you engage high beams truck dies.

I have checked for bad grounds, fuses, relays, etc. I have not yet changed headlight switch itself as I really dont think thats the culprit but I could be wrong. Anybody else dealt with this same issue?

 

good one ! I would throw a switch at it, not expensive at all. Amazon has one for $28.

 

I feel it's a bad security module.

 

Fascinating, please post what you find. I'm no help but the headlights on our '08 F150 are always on with ignition, but get brighter when switched to low beams. Almost like DRLs. But no problems like you're experiencing

 

No idea here, but have you scanned for codes with a good scanner such as ids or Forscan? Will it crank with the high beams on. Have you checked ALL the grounds? Bad grounds really do some strange things

 

Im late to the party did you check the grounds at the passenger side fuse panel? There are 2 together under the plastic cover. I've seen these be a issue with lighting. Just a thought