I have a 07 f150 and when I go to shift it into 4h the lite flashes on and off really quick truck acts like it's engaged in 4h but I can not tell. I can shift it down to 4l and the light comes on and makes a clunk sound when it's egaged... I am putting the truck in nurtral first and at a complete stop befor I shift it into 4h or 4l. When I'm driving the truck in 4h I notice it's a lot harder to turn so I think it's engagin bUT cant tell with oUT the light o . And when it's in 4l you defently can tell. When I start the truck up all the lights come on like normal and go off. So what could be the reason why my 4h light is not coming on could the tcase be low on fluid

 

Sounds like everything is working as it should sans the dash lights. I would take a guess that either you have a loose connection somewhere or the lights in your dash are burnt out.

 

You need not stop to shift to 4H... SOTF = Shift On The Fly. You can select 4H at any speed up to 55 mph.. and I agree with Rivera.. sounds normal.

 

So the dash light does not stay on when is in 4 hi but it is engaged? If so that's the exact symptoms mine had. Was as simple as replacing the solenoids. It's about $25 at almost any parts store and takes 10 minutes to replace. Search IWE solenoid here on the forum and you'll see it's simple. That's where I'd start.

 

^^^ yep ^^^