I'm posting this for my brother-in-law. Both of his headlights stopped working on his '96 F250 PSD. All of the exterior/cab lights are still working. So far he has replaced the pull switch, bulbs, and some multi-function switch under the hood. But still no headlights. Any suggestions?

 

If multi-function switch on steering column already replaced then check fuse #19 ... 40A under hood fuse box.

 

He's checked all the fuses with a multi-meter for continuity. But you say there is a multi-function switch on the column? I think the one he replaced was under the hood.

 

Both low and high beams? Has he tried the beam switch to see what happens? Does the high beam indicator on the dash come on? Has he checked for voltage at the headlight connectors, with the black probe of the meter on the battery negative?

 

Correction: it was the multi-function switch on the column that he replaced.

Yes, both high and low beams are out, and tried high beam switch but nothing. He checked the voltage at the pull switch and both wires had power leaving the switch, but I think that's it.

 

Have him check voltage at the light pigtails themselves, but using the battery negative on the meter black probe. Then do the same, but with the black probe in the ground terminal on the pigtail. The objective is to determine if the ground wires on the harness are not grounding.

 

Will do. Thanks!

 

If you have a tilt wheel , look for a broken wire ....

 

So there's voltage leaving the pull switch but none at the bulbs. Any ideas before we have to trace the lines looking for a short?

 

Check the connections at the firewall connectors. I don't recall which one it is, but that's the only place where all of the wires for the headlights would make a connection. High beam and low beams are both out?

 

Yes, both hign and low beams are out. His wife remembered that the lights flashed off and on the last time she adjusted the tilt column; so we're thinking it's in there right now.

 

So my brother-in-law came over yesterday so we could work on his lights. After a couple of hours of testing connections with a test light, we confirmed that there was power leaving the multifunction switch for both high and low beams, but it was't reaching the bulbs. Finally we remembered that the PO used it as a plow truck. After tracing the 'new' wiring harness for the plow lights, I found a toggle switch hidden in the tray under the wts light. One flick and the headlights were working again.

All that time and nothing was wrong to begin with!

We think his wife accidentally switched it but sticking something in that tray.

Thanks for the help anyways!