I have an 01 super cab 4x4 with an 05 4.0 motor and trans. 4x4 will not engage at all. I've replaced the switch, the tcase shift control module, and the shift motor. I Even replaced the indicator bulbs in the cluster. Still nothing. It was working before trans was rebuilt. I don't know what the hell to do.

 

I assume it works in 2WD?


So what is happening is that the shift motor is not turning so transfer case stays in 2WD.

When you change selector to 4WD high what do the lights do?

Flashing then steady light usually means shift motor moved to correct position, just flashing means it did not move.
No lights = no power

The shift motor itself has the position contacts inside, so when motor turns these contacts are moved into a position where 2 line up and pass power back to 4WD system module to confirm correct position and light goes steady.
You can usually hear the motor turn.

Have you looked at the fuses.
In engine fuse box #13 20amp
In cab fuse box #5, #9, #10, #11 and #28, all play a part in 4x4 working

This is for 2001 Ranger 4.0l fuse numbering

Could just be some wires got pulled on when removing or reinstalling trans, so also check connectors to make sure wires are in all the way, if a pin gets pulled on it won't make contact with other side of connector.

 

I checked the fuses by way of test light. Cab fuse #28 has no juice in the hot leg. I'm thinking about running a hot side jumper wire after work.

 

Fuse #28 will only have 12volts when key is turned to START
It is a Neutral sensor

 

Ok so all that checks out. I've got power to the shift motor and the position sensor. Back tracked a little. I have no power at the connector to the switch on the dash. I'm befuddled.

 

The switch is similar to cruise control switch, I wouldn't think there wouldn't be much voltage there, maybe 5volts.
switch has 3 resistors inside, 1 for each switch position.
Yellow/blue wire and White/blue wire are the control wires
Other 2 wires are for dash lights, back light

When switch is off voltage should still be passing thru switch, looks like from white to yellow as yellow is listed as signal return.

Both wires are hooked to 4WD module

 

I had this problem ! With the e-brake applied engine off ignition on shifter in netural place the 4x4 switch to 4x4 loosen the 2 screws on the switch on the trans & slowly turn to time the switch as it will engage when you make timing contact area . secure the screws. My thoughts Bud

 

Done the switch timing resync with no results. Have a multimeter on the switch now. Have 3.8v in 2wd 2.9v in 4H and 1.75 in 4L.

 

That should be fine, as long as voltage changes with switch position the 4WD module should respond to the change in voltage.

 

Could it be a vacuum problem? I think I have a sketchy trans valve body too. Could that be it?

 

Take a spray can of WD-40 with the engine running an spray each hub an all vacuum lines .
If there is a leak the engine will rev up exposing the leak .
My Thoughts . Bud

 

I had no results from this sir. Thank you for the help so far. Any other ideas?

 

Your 2005 doesn't use vacuum hubs, that was 1998-2000 PVH Rangers

 

So then could it be from something on the transmission?

 

Here is the wiring diagram for 2005 model year, engine size doesn't matter.

no vacuum involved, and transmission only needs to be in Neutral and foot on the brake when shifting to 4WD Low