I have a 2005 STX F150 4x4. My 4 Wheel Dr. light did not come on. So I replaced the switch that screws into the transfer case, but it still does not come on. However, when I start truck. The lights on the instrument panel light up.

 

do you know if it has a solinoid i had the same issue in my 93 model and that was the issue it got submerge in the water for long periods of time and it fried it.