2006 f150 4x4HI light doesn't work
 

I need some help. I have a 2006 f150 STX 4x4. The 4x4hi light does not turn on when I put the transfer case in 4x4hi but comes on in 4x4low. The truck has the newer IWE Solenoid with the water sheild and there aren't any grinding noises like the 4x4 is trying to engage in 2hi. Is this the solenoid going bad again or something else?

Does the 4hi or low engage? It wouldn't heart to pull the switch And see how its illuminated as well.

The light occasionally comes on ( ie works one day and not the next, or will come on momentarilly sometimes when shift the transfer case into neutral) The 4WD appears to be working even when the light is not.

4wd light comes on via t-case shift motor, shift motor will not engage untill IWE solinoid says its time. Those are your 2 suspects. A dealer can scan the 4x4 system for DTCs and point you in the right direction.