4x4 not engaging

[I-Climb]

94 ranger 4.0 manual push button manual hubs.

When I push the button nothing happens other than my headlights dim for a second. No 4x4 lights light up even when I turn the key on and start it up. I did the push button test and the light blinks like the book says. Seems that all my fuses are in good working order as well. I was told it could be a vacuum issue?? Do the 94s have vacuum hubs? This is my first fanger and don't know a lot about them.

Any ideas?

 

[RonD]

Welcome to TRS

No, pulse vacuum hubs(PVH) were only used on 1998-2000 Rangers and not even all those got that bad idea

Couple of tests
Unlock both front hubs and move truck forward or backwards, watch front axle, it shouldn't rotate
Lock both hubs and repeat, front axle should now rotate

On the back of the transfer case is the electric shift motor, these often fail when older, but can be cleaned or replaced.

Pictures here: http://www.explorerforum.com/forums/index.php?threads/how-to-rebuild-4x4-shift-motor.123542/

If you scroll down to pictures 5 and 6 you will see the Contact wheel(5) and contacts(6)
These are used for the 4x4 control module, so it can tell where the motor/shifter is at at any given time, AND...........it turns on the 4WD lights.
When you select 4High the 4x4 controller will send 12volts and Ground to the shift motor, IF MOTOR IS WORKING, it will start to turn and contact plate will also start to turn, this makes and breaks circuits on the pins touching the plate, Controller knows, for example, when pins 1 and 4 are connected via this wheel then shifter/transfer case is in 4High position so it stops sending power to motor, AND it also turns on the 4high light once contact wheel is in the correct position.

Most common problem with this setup is the electric motor, it uses brushes to power the rotor, like most electric motors, but how often does this motor get used and how often do you hit speed bumps or other bumps on the road
With disuse the brushes corrode or get dislodged so no longer make contact with the rotor
When you select 4WD nothing happens because motor is not turning, so no lights either.

It could also be the 4x4 module, although less likely, read here for that: http://www.therangerstation.com/tech_library/4wd_control_module.html


Just as a future heads up, you should shift transfer case once a month just sitting in the driveway, don't need to move truck at all.
Shift to 4high and then shift to 4low, then shift back to 2WD, that will keep motor cleaner and gear lubed, just takes a little time.
And if it doesn't work............better to know now when you don't need it than to find out it doesn't work when you do needed, lol.

And since you have manual hubs already, you can get a Shiftster, they are making them again
You remove the electric motor set up and bolt Shiftster on in its place, this allows you to manually shift transfer case, so no wondering if 4WD will work
Yes you have to get under the truck to shift it

But since you have manual hubs you can drive in 4high in the winder with hubs unlocked, and lock the hubs only when you want 4WD, doesn't hurt anything to do this.
You will get best MPG in 2WD, but certainly not a big difference.