Alright here's the problem I have a 2003 FX4 Supercrew shift on the fly. Turn the switch and nothing happens no sound and no noises. With truck running pulled the vaccum lines at the fire wall one line I can feel the vaccum the other I couldn't, truck still running pulled lines off of T-Case and no vaccum on either line. All fuses are good. Hunting season is around the corner so I need it fixed.
Thanks in Advance
Scott

 

check the solonoids on the fire wall i had one go bad once, dose the 4x4 light come on, also somthing else you can do is take the vacum lines off the motor on the front diff and manually engage it if you can then you know its vacum

 

The light does not come on, how would I go about checking the solonoids and to manually engauge the front diff. Thanks FireFighter1416

 

well now it sounds like there could be problem with the electric motor on the transfer case i've never delt with anything on that deal just the front end, theres a plastic cover on the front axle that protects that motor i was telling you about, if you take it off and pull the vacum lines off you can manually engage the front end by moving the lever on the motor, another thing you might make sure is that there are no wires hanging down or have been cut by your transfer case if you do a lot of off roading there could be a chance your wires got caught good luck

 

The 4x4 control system is way more complex than you think.
The switch signals the GEM module which then operates the relays, front axle vacuum motor engagement and the transmission motor then returns a signal to turn on the dash lamp when these operations are performed.
With no trouble shooting to see what does or does not happen and no info at this point, there is no clue to what the problem might be.
Could be any part of the system.
Best thing to do if you are set on repairs yourself is to first learn how the system works then begin to see what is not responding.
Get a Ford service disc for your year range that has all the info on it for these systems.

 

I finally got my 4x4 working again, thanks FireFighter1416 you were correct the electronic motor on the transfer case was the problem. I tapped on it and it started working, so now that Gustav and Ike has left us alone I can put the new part on. Thanks again for all yall help.