Ford Repair: Headlight failure - bulbs & fuses good, many different reasons, test light

Question
1998 Ford Explorer 2WD 4.0L EFI SOHC XLT trim
My headlights have stopped working.  I have checked the bulbs and fuses and they seem to all check out good.  When I hold the multi-function switch IN (pull it towards driver) - Flash to Pass - the bright lights come on but upon release they go off again.  All other lights (turn signals, running lights, brake lights) appear to function normally.  When caught out at night I have been forced to just hold in on the multi-function switch forcing the lights to be on bright but as you can imagine other drivers don't seem to like this much.
As a side note I have had a short in the electrical system for the radio.  The radio display will display only briefly if at all.  I don't believe this is connected to the headlight problem but I thought I had better mention it.


Answer
Hello Chris,
          The headlight power goes through the multi-function. Those switches fail for many different reasons, including yours. Not seeing the vehicle, I would say that is your most likely cause, however I always like to verify it with a test light and a wiring diagram. That is where my job starts to get hard :-) Good Luck!  Shaun.