Please help

I have a 2004 FX4 4x4

Four wheel drive is not working!!!!!

Turn the dash switch to 4High or 4Low and the lights come on in my dash gauge cluster. So my 4x4 lights come on as if the 4x4 is working but my front wheels do not turn.

What I have done:

With help, drove the truck forward while I watched the front drive shaft going from the transfer case to the front differential. Did this in 2WD and then in 4WD high. While driving forward in 2WD the front drive shaft did not move. Once put into 4WD high and driven forward the front drive shaft was turning.
I guess this tells me that my transfer case and shift motor are working?

I jacked up my driver side front wheel and turned the tire by hand while the truck was running in 2WD. The tire spun freely and the CV axle (half shaft) did not turn. Then turned 4x4 dash switch to 4WD high and turned the tire again by hand and the CV axle turned while turning the tire. I guess this indicates that the IWE actuator was working....I guess???

repeated the process above for the front passenger side of the truck and the tire would always spin freely regardless if in 2WD or 4WD. I could not get the CV axle to turn while spinning the tire on the passenger side when the truck was running and switched to 4WD

I checked the vacuum solenoid near the battery mounted on the firewall. The vacuum line suppling vacuum to solenoid was working and pulling vacuum. I did a series of test in conjunction with the dashboard 4x4 selector and the Vacuum Solenoid seemed to be working properly.

Crawled under the truck while the engine was running and pulled the vacuum line off the nipples of each IWE Actuators (drive and passenger side) put my finger over the lines and felt decent vacuum at each end of each vacuum line.

So dash switch and 4x4 light works stays on solid and bright does not flicker
Vacuum solenoid and vacuum lines seem to be working
Transfer case and shift motor seem to be working
Driver side IWE actuator seems to work

Front passenger side Actuator does not seem to be working???

Why I am so confused about this is because in HOURS of Internet research it seems that this Actuator is not allowed to engage by vacuum pressure. When I disconnect the vacuum line to the passenger side actuator I expected to hub to lock, but it did not, the tire would turn but the CV axle wouldn't?

If I replace the passenger side IWE actuator will this fix my four wheel drive???

Or is there something else I am missing???

Please Help

Any Advice will be greatly appreciated

Thanks

 

yes, your on the right track. The IWE is STUCK. You need to pull apart and check / rebuild / replace......... there is a post that discusses this.

 

https://www.ford-trucks.com/forums/8...then-some.html


from the above........
Remember the 4WD engagement or lack there of is considering that you shift motor on the transfer case is working properly.

If you suspect that your system is malfuncting and you are not able to test it right away or want to drive and not damage anything, disconnect the line coming off the intake at the check valve and plug both ends of the line. This will not allow any vacuum to reach the system and leave your hubs locked in all the time. This is fine and wont cause any damage as long as the hubs lock correctly. The half shafts and front driveshaft with the front differential will turn but the 4WD will not be engaged. You might notice a drop in MPG, but it is now safe to drive.