Hey guys pardon my auto jargon but I don't lots about cars but a friend of mine who does some side work as been working on this issue I been having with my 2004 ford f150. I have no lights on dash that indicating 4x4 on. When I move switch nothing happens. He changed the actuator 2 days ago nothing the fuses in side door passenger lower panel all check he tested them. He check the solenoid and vacuum lines and there all fine. The other think I can think of is if could be something under hood the auxiliary fuse box the only problem is previous owner installed a cold air intake so can't even get in that box could it be possible it's one of the relay fuses in there ? I can send a pic on here and show u what's going on under the hood.

 

There is a small fuse box under the hood with a 4x4 fuse/relay in it. Have him read power at the SOTF switch.

 

Ok thank you..

 

A few minutes and that simple cold air intake would be removed by a screw driver...