First of all, I've read numerous IWE threads from start to finish looking for the answer to my problem. Therefore, my inability to find the solution to my problem isn't due to a lack of research.
Secondly, I'm reasonably mechanically inclined as I rebuilt the trans in my 05 5.4 SCrew (104K miles) about a year and a half ago and its still running great. Now that that's out of the way, one day (since rebuilding my trans) my 4wd worked perfectly, the next time nothing...ie, truck's running, in park, drive, neutral...etc, I turn the switch and no lights come on, no noise from the xfer case (no clunk)...nothing. I've had the IWE solenoid replaced with the one with the 'rain shield' on it, I've pulled the 4wd actuator motor and tested it with 12v (moves flawlessly), I've rechecked the IWE solenoid with voltage, and checked resistance (to make sure the electromagnet that makes it function wasn't blown), I've checked for vac and leaks...aside from the vac pump method, I've pulled the switch and shorted across the pins in case the switch was bad, I've checked all associated fuses, checked the connectors at the "GEM" and of course the xfer case actuator motor. In a fit of desperation, I even disconnected the ground on my battery for 10-15 minutes in hopes that (as I read somewhere a guy "fixed" or "reset" his this way) something would be reset.
I've read somewhere that the system "waits" for a signal from the IWEs to tell it to engage the xfer case actuator, yet I have also read that they operate independently. ANY AND ALL HELP AND ADVISE ARE GREATLY APPRECIATED AS I AM NOW STUMPED. Sorry this question is so long, but thanks for reading.

Jeremy

Oh, and anyone that wants the 500+ page factory service/repair manual for the trans, I can probably scan it and make it available.

 

I know this will sound dumb but get under the truck and whack the motor that puts it in 4wd with a rubber mallet, it looks just like a window motor on the trans. There known for sticking..........

 

That was one of the first things I tried.

 

Do you have acess to a scan tool that has the ability to read the other modules of the truck - G.E.M. specific? It sounds like you have checked everything posible (input/outputs), it does leave the only thing posible (MODULE) unchecked. You might need to visit the dealership, or check your independents ability to scan the G.E.M., for this repair.

 

I have "access" to that, yes.

 

Side note, I had a flywheel crap out on me. It was after the flywheel that I noticed it not working, but all of my connectors are of course connected. The wiring harness that runs over the bell housing has 4wd related "stuff" in it, if I'm not mistaken. Is it possible I cut a wire in that harness? Looks like I'm breaking out the multimeter and chasing wires as well.

 

check all your harnesses for continuity from the swith on back to the transfer. and inspect all connectors to ensure they are seated properly. sometimes it may look good, but it isnt. of course you'd see that when doing your continuity checks.

 

did you get any codes? list all of the codes if posible

 

No codes. Going to check my harness/connections and continuity readings in the morning.