Ok, I have a '98 F150 4.6, my headlights are not working, no high beam, no low beam, bulbs are new and good. I installed a new headlight switch, and all fuses and relays seem to be functional. Has anyone expierenced this??? Brakes, blinkers and running lights all working normal.

 

I have a similar problem with my 98 f150. no highbeams or highbeam blue light. I have replaced arm and still not working. ????

 

Edit: If flash-to-pass also does not work, check F8 first.

Check fuse F8 in the underhood fusebox. It feeds the DB/O wire at the main headlight switch. The output of the switch is the R/Y wire that goes to the MFS. Low beam power comes out of the r/bk wire, goes to fuses in the instrument panel box that protect each side individually.

Steve

 

Check fuse F16 in the instrument panel fusebox. It is between the output of the MFS and the hi-beam bulbs and protects the high beam-only circuit.

Steve