I have a 2006 F150 King Ranch
I tried to engauge the 4wd and nothing. no lights hi or low. I checked all the fuses all seems to be good. HELP

 

I found that I have the same problem and cannot seem to figure out what is going on. If anyone out there knows, or has any suggestions that would be greatly appreciated.

I was pulling someone out of the snow and put the truck in to 4 wheel low. The engine shifted in to the low gear but the light did not come one. While I was pulling him out the back tires were spinning but not the front tires.

 

Possibly a bad shift motor, or bad switch in the dash.

 

vacuum solenoid, simple fix, same thing happen to me