Need help with lights on a 2000 f-150! Here's the story, It started with hitting the trailer brake unit with my knee and all of a sudden my dash/instrument lights went out! Checked all fuses and all were good! Shut off the truck and the headlights will not turn off unless the two 10amp fuses are pulled for each side headlight. I then pulled the headlight switch out and disconnected it. The lights still stayed on! I have sinced disconnected the trailer brake unit and still nothing! Does anyone have any idea of what could have happened? Thanks for any help!

 

HAs there been any additional work to the truck ?

Pulling the main headlamp switch out, cuts power from BJB Fuse to the main headlamp switch, which in the main position, MFS in low position feeds CJB fuses # 26 & # 28.

That sounds like something was changed on the truck, on the surface.

Do you have DRLs on the truck.

Do the instrument panel lights work now ?

Did you use the trailer tow brake adapter pigtail to hook up the trailer brakes ?

 

Thank you for the information, but shortly after i posted for help, I went back through everything and overlooked a blown fuse #6 in the box under the hood. Replaced the fuse and all is well! Any idea of why the headlights stay on when that fuse goes out? I am pretty new to this sight, but i must say it is very informative and everyone seems very willing to share their knowledge!

 

BJB ( battery Junction Box aka= under hood fuse panel ) Fuse #6 feeds the main light switch, the park lamp relay in the RPO relay block ( RPO relay block is for Auto Lamps).

AutoLamp - RPO Relay block section of circuit
This is hot at all times to the relay coil, and to the NO contacts on the relay. The ground side of the relay is controlled by the RAP ( Remote Anti-Theft Personality module ).

The Other side of the NO contacts on the relay go to the parking lamp circuit.
The headlights in the Autolamp circuit are fed from BJB Fuse #3 if you care to know

Main Light switch section of the circuit

This section via the main headlamp switch feeds the remainder of the auto lamp circuit, the GEM and CTM and the belt minder of all things, as well as CJB fuse # 18 5A for the instrument panel dimmer illumination circuit, as ckt 14 / brown / parking lamps circuit.

That is the what and where part of our show today.

For the why got me, it does not make sense if the main headlamp switch was pulled, that they would still be on.

Sorry, I don't have a good answer, considering if the fuse feeding the CJB fuses # 26 & # 28 is taken out.