I have a 97 F-150 and the 4x4 is not working. The transfer case locks in but front diff doesn't. I checked the soleniods and I have no vaccum to the input side of them. I am going to check voltage to make sure thats not the problem. But when I put in 4H the low range light comes on. the 4x4 light doesn't come on at all. Only when I'm starting it. Any help would be great. Thank you.

 

Putting in 4H and Low range light comes on is a problem.
Not supposed to work like that.
The fire wall solenoids must have engine vacuum to transfer to the axle actuator for its operation.
Here is how the system works:
After selecting 4H the case motor runs to first position.
This connects through a harness to the fire wall solenoid to pass vacuum to the axle actuator that engages the right side axle.
What to check:
Is the case motor running to its first position and not stuck in the second position and rotates back to 2H when 4x4 is switched off.
Is there vacuum to the fire wall solenoids with engine running?
Bottom line is the case motor must run to first position, operate fire wall solenoid, apply vacuum to front actuator.
Only when the fire wall solenoid operates will the dash 4x4H come on providing they have vacuum and power to operate.
4L is the second case motor rotation position so gear reduction occurs, the shift sked changes and the 4L light comes on. the rest stays the same.
Turning the system off just reverses all actions.
Good luck.

 

I was looking for someone to help me out on knowing how to read out the schematic from the battery to the shift motor on the 1997 Ford F150 Borg-Warner transfer case. I get lost on finding the wires and knowing what they control and how. I could start from the motor harness if you could tell me what the pins are for and what they are supposed to read and how i could know if my current is right on each wire. Any help would be very helpful. thanks,

 

Mine is a manual floor shift. No t-case shift motor.

 

Thanks, hoping someone might pick up and send me something. I guess i will try to see if the switch has voltage first and if so then try to find out where the signal is sent from the switch. I do not know if the constant voltage at the switch comes from the relays or the battery positive at first and then to the shift motor or the relay to the shift motor. I get real confused on the actual route of the wires. thanks,