Someone please help me! I have a 04 FX4 extended cab. I noticed my reverse lights were not coming on while my headlights was off. I leave my headlights on auto turn on. Well I checked my fuses and found #10 fuse was blown which is trailer tow back up lamps relay(PCB1), trailer tow parklamp relay (R201). When I replaced the #10 fuse my reverse lights worked without the headlights on, but when I turn on the headlights and then turn them off my parking stay on. the only way I can get them to shut off is pull #10 fuse. Also, my back up sensors do not work but I think this do to a broken sensor. Does anyone have idea how I can fix this?

 

Any modifications to the truck ?

do you have anything plugged into the 7 pin trailer tow adapter when this happens ?

When you say turn the headlamps on, off, the parking lamps stay on, is this turning them to auto on or to the actual on position ?

Are you sure the parking lamps are on, or is it the stop / turn lamps at a decreased brightness ?

Is the 7 pin trailer tow adapter clean ?
- Check the back where a trailer plugs in for corrosion between the pins, and check the back where the wiring goes into the shell, this can get corrosion in there as well.

 

Thanks for your help SSCULLY. I checked the connections for corrosion and found a jumper wire rigged up over a plug up by the frame. I removed it and repaired connections and it fixed my problems. I have no idea what the jumper was for, but I cannot find anything else not working. Who knows. I really do appreciate your help, with out your direction I probably would not have found as quick as I did.