I need some help; I have a 2002 Ford F150 Super Crew 4x4.  I have an electronically controlled (on the dash) shift on the fly 4x4.  I can shift into 4H (I feel it, and 4High light on dash comes on)  when I switch it back  to 2H the light on the dash turns off, but does not disengage (stays in 4H).  I tried a few things to get it to disengage, like putting the truck in neutral (while still moving forward) and rev the engine, sometimes this works, I tried turning the truck off while moving forward and restarting it also.  I’m not sure if it disengaged before or after I did that.  I was thinking it may be a vacuum line, but wanted to get info from those who have experienced this in the past.

Thanks,
D

No experience with Ford electronic shift on the fly, but it may be solenoid activated rather than vacume activated.

www.4x4posi-lok.com/app_ford.html

based on what i could find on google, it's a vacuum system

Expect the t-case to be shifted by an electronic servo type drive.  Crawl under there and look for a windshield wiper motor looking arrangement hanging on the back or front of the t-case.  There should be a shaft on the opposite side that you can insert a 3/8" drive extension into to manually shift it.  Note the previous is how the older (mid 90's) electronic shifts worked.  I wasn't aware that the Fords had an axle disconnect as well, but it looks like they do.  

Your experience is why I detest electronically shifted drivetrain parts.  

My '08 F350 is the same way. When I shift into 4L, the light stays on 4H and only goes into low half the time. I then have to shift into neutral, let the load off, then reverse to get it to engage. I miss manual 4x4's.

Thanks for the help, I was going to take a look at the T-case yesterday, but I was invited to go Dove hunting instead.  Needless to say I decided to go hunting.  I plan on looking at the T-case today.  I have not tried going into 4L, I guess I could do that during lunch.  If all works fine but doesn’t shift out of 4H to 2H, do you all think it maybe a bad “windshield wiper motor looking arrangement” (fastang50), or the vacuum line that controls that unit?

Thanks,
D

eta: short answer to your question, yes, I'd bet your windshield wiper t-case servo is on the fritz.  the below, do it both into and out of 4wd, will help you figure it out.  Mind you that wo any drag on the parts it may shift into and out of 4wd easily.  In that case, find the manual override on the selector shaft and try it with it on flat ground.  

Don't RUN YOURSELF OVER!


Should be easy enough to find out.  jack up all fours, you might want to set the parking brake also.
With the vehicle in park 2wd, can you freely turn the front drive shaft?  I hope so.
Do the front wheels turn mechanically with the shaft?
-if yes then you have no central axle disconnect or you do and it's jammed 'on'
-if no then you have a central axle disconnect that isn't engaged, which is fine
Now turn the key to run (or start the car if you're feeling tough, leave it in park!) and put the thing in 4hi
Now the front shaft should be locked with the back shaft and in park you shouldn't be able to turn it
If you had a central disconnect it should have also locked up
If the shaft is locked but the wheels still spin free then you have a central disconnect issue

You should be able to figure out your woes from that hit list, if not let us know.

Don't know why the Mfg's had to screw up a 100% reliable mechanical system with this trash.  

Thanks, I'll have to try this.  I played with the 4H a bit on the beach a bit, and no problems.  I'll post what i come up with.

Thanks,
D