I have a 1999 super duty 7.3 4X4 that doesn't go into 4 wd when the dash switch is positioned. I removed the transmission case motor and applied 12 volts and the motor turned but I don't understand the other modular connector and why the transfer from 2x4 to 4x4 doesn't work . I have checked the fuses and relays all are good. Help

 

It could be the vacum, does it go into 4x4 when you lock the hubs?

 

welcome to FTE



when truck is running does the defrost switch to floor or vent?? if not.. you have a vacume leak.. most likely from the line going to the wheel..this is one reason im glad i have the lever on the floor..

 

On my dads excursion one of the wires going to the transfer case motor was broke...