My headlights have been blinking on and off for a few days.
Now, the only time I can get any headlights at all is to pull
back on the turn signal/highbeam switch. My parking lights
work fine. Please help, my Haynes book doesn't touch this
topic. Thanks in advance.

 

I should ad the truck is a 4.6 XLT, 166,000 miles.

 

i would say either a headlight switch or a multifunction switch

 

In my case, I had the same symptom (windshield washer switch also quit). The MFS was the problem - my Haynes had a good description of the ritual in removing the MFS - the only special tool you need is a TORX bit. I also used my Haynes and an ohmmeter to verify the headlight and windshield washer switch was out on the MFS. About $100 at Ford.

 

if you do find out that you need the switch, let me know i have a brand new one in the box

 

Thanks. I took the old switch assembly to the Ford parts department
and purchased a new one. The windshield washer switch hasn't worked
well for a long time. It all works perfectly now.

I couldn't figure out the name of the thing until I took it apart
and realized it was a switch assembly. It was corroded inside
and a piece was burnt inside as well.