I have a 99.5 F-250 4x4 Crew Cab truck. I put my truck in 4x4 high with my dash switch and when I went to take it out it would not come out of 4x4. I then manully had to go under the truck to power the motor off of a battery to get it back to 2wd. I have checked all relays and fuses and I even have put in a new switch. Nothing seems to be kicking it back out after the switch puts it in 4x4 of 4x4 low. Also I am still getting power down to the two wires that hook up to the motor on the transfercase.
Thanks
Dude

 

I don't have a 4x4, but look for a vacuum leak (cracked/broken lines, etc.). I'm pretty sure the SOTF 4WD uses a vacuum switch...

 

This is why I wanted manual shifter and hubs. All this vacumn stuff really sucks.

 

I bet your A/C only blows out of the defrost vents no matter where you have the selector. If so it is a vacuum leak. start at the vac. pump on the pax side fenderwell and trace the lines off the pump, make sure there are no cracks or breaks all the way to the back of the hubs. there is also a vac. manifold behind the glove box check to make sure that line going to this is not cracked or split.
The vac. pump controls the ESOF and engages the hubs, as well as the air diverter for the a/c. the default position for this diverter is through the defrost vents.

 

I bumped this one back up so we could try to help this fellow. He's not saying his hubs won't unlock, he's talking about his transfercase (electric not vacuum operated). Rethink this one and see if we can help out the new guy.
Joe

 

So can you power the shift motor manually in and out of 4wd?