I have a 2001 F150 with the V6 engine and manual transmission. The problem I am having is not being able to turn the headlights off with the dash mount switch once the engine has been started or after it has been turned off. Another possibly unrelated symptom to this problem is the fact that I have no dash or instrument panel lights either. Both these controls pass through the same dash switch assembly which I have replaced and incidently had no effect on the problem. While the engine is not started and after momentarily disconnecting the battery from the vehicle the light switch on the dash then functions correctly in its positions turning headlights and parking lights on and off in its 3 positions. However, once the engine is started and even after the engine is stopped and keys removed the dash light switch then has no effect on the headlights. The headlights then remain on until the battery is fully discharged or the main 30A headlamp fuse in the engine compartment is removed and replaced. Removing and replacing this fuse apparently deenergizes a stuck relay somewhere which allows the lights to turn off. Interestingly enough removing and replacing either of the L/R headlamp fuses located in the fusebox inside the cab only extinguishes the light when the fuse is pulled but the light comes back on when the fuse is replaced. Also, this car is not equiped with DTRL. Also it is equiped with some pseudo alarm system which frequently malfunctions and begins alarming and flashing all the lights when I have not driven the car in some time. I would very much like to disable or remove the crappy ford antitheft system if anyone knows where that is located. Any advice or suggestions onmy lighting proble are much appreciated.

Thanks

 

I would start by disconnecting the "psuedo" alarm system since you said it has/does malfunction and see if the headlights work normally. If the lights work normal......viola!

Mike

 

Well I called it a pseudo alarm becasue it doesn't really seem to function like an alarm. It 's actually a FORD passive antitheft system called SecuriLock which arms automatically when I lock the doors with the power lock switch before exiting the vehicle. A dash light flashes the word "Theft" periodically when it is armed. I'm uncertain how to disable this feature but if someone can tell me how I would be happy to give it a try. Also I am missing the key fob that came with the vehicle. I believe the key fob interfaces to the alarm system. Anyway, I'm not convinced that has anything to do with the lighting problem but I would gladly disconnect it if I knew how just to eliminate a possibility.

I was able to get my hands on some wiring diagrams someone else posted trying to resolve another lighting problem and after looking these over I can see there is no relay for the headlights. However, the system sure acts like there is a relay the way removing and replacing the headlight fuse in the engine compartment fuse block makes the lights go out and resets the circuit allowing the light switch to function normally until the next time the car is started. Crazy!

After reading this board it's no wonder to me that Ford is nearly bancrupt! My 8 year old nephew could design more reliable circuits.

I'll probably have to wire up my own headlight switch to bypass all Ford's crap engineering just to make the lights function properly.

 

These diagrams show a multifunction switch in the path for the power to the dash lights and headlights. Since I have problems with both these circuits and this switch is in common with both I am starting to think maybe that is worth taking a look at. Unfortunately that switch is in the stearing column. Not lookign forward to that approach to solving this. Since all this switch is supposed to do is provide a way to select between low beams, high beams and "flash to pass", whatever that feature is, It might be easier to drill a hole in the firewall and rewire the light circuit bypassing the stearing column entirely.

 

The Multi Function Switch shouldn't be that difficult to change. There should be two screws (accessible from the bottom of the column) that you should be able to take out and remove the upper and lower plastic column covers. You should be able to remove the MF switch by removing two screws that hold the switch on to the column. The "flash to pass" (when you pull back on the multi function switch) allows you to briefly turn on the high beam lights while passing another vehicle.
I had a similiar situation this morning with one of our Crown Vic PD veh's. I think the LCM is bad. No headlights, park lights, etc. Turn on the code 3 equip, headlights flash back and forth. Turning on the headlight switch, and pulling back on the MF switch, (while in code 3) dash lights started to flash rapidly. If these trucks have a Lighting Control Module (LCM) could be the LCM is faulty. I think the LCM takes the place of some relays.
Hope this helps and good luck. I'll do some checking and see if I can't find a pic of the MF Switch.
Mike