4wd not working

[black06xlt]

i have 1996 ranger 4.0 auto 4x4. the 4wd isnt working. i changed the switch in the dash and the motor on the transfer case and checked the fuses. need help with thus issue?

 

[RonD]

Do the 4WD lights come on when key is turned on, the Bulb test?

What do you hear when you try to change transfer case setting?
You should hear relays click, and if you do have you checked if front drive shaft is turning in 4WD?

Do the 4WD lights flash?

There are two fuses in engine bay fuse box #7 and #16 both 20amp, check them
Also fuse #27 in cab fuse box

In 1996 the GEM(generic electric module) controls the 4WD
The switch wires go to the GEM and the Shift Motor position wires go to the GEM

The two Motor wires go to a Dual Relay module that is also connected to the GEM
This relay module is called electric shift module.

The GEM runs the system, and if motor is not working GEM will flash the 4WD dash lights to show an error

The GEM also controls wipers, power windows, dome light, pretty much anything electric in the cab
So..........is there any thing else in the cab that isn't working or intermittently working?

 

[black06xlt]

the lights flash on the dash

 

[RonD]

Flashing 4WD lights means the shift motor is not moving

The GEM is connected to the dash switch and the dash lights
The GEM has 5 wires that go to the Round Gear case on the shift motor
These 5 wires are connected to contacts inside the shift motor
Pictures here: http://www.explorerforum.com/forums/index.php?threads/how-to-rebuild-4x4-shift-motor.123542/

GEM activates two relays in a separate box(shift control module) to send power to the shift motor.
GEM waits for the contacts inside the shift motor to change, open and close, this tells the GEM the motor is working AND what position it is in, 2WD, 4high or 4low
If contacts do not change then GEM flashes the lights to let driver know there is a problem

So either GEM is "lost" can't read contacts, or Relay box is bad
Assuming you have tested all fuses

The fact GEM flashes the lights usually means GEM is OK, usually is the operative word
Money would be on shift control module(relay box), if shift motor tests as OK

 

[black06xlt]

where is the shift control module located?

 

[RonD]

??

Could be behind Radio with GEM or in passenger kick panel, maybe under glove box

Ford moved stuff like that around