I have a 2000 F350 Super Duty with On The Fly 4wd that will not go into 4wd, I checked both fuses and found the 30 amp maxi fuse blown, replaced the fuse still no shift, I checked both relays for actuation and just in case replaced said relays.
Connected My Snap-ON Solos Pro and tested the switch, it shows the switch is working, but does not show any shifting
The shifter on the transfer case does actuates when voltage is applied. I can't see any chaffed, broken or grounded wires and I get no voltage at the transfer case.
The wiring diagram shows an Electronic Shift on the Fly solenoid and a four wheel drive control module > My quandary is where do I go from here??
Frank

 

mine is the same , have you checked the vacumm that actuates the locks?

 

A common issue was vacuum pump out by the right battery,, and of curse line/hub vacuum leaks. Will they lock in manually? NON ESOF