New 4x4 Module, but still no 4WD

[Squirrels]

So after researching the forums on why my 4WD lights would not illuminate after pressing the dash buttons, I came to the conclusion like everyone else with a 2002 explorer that my 4x4 module needed to be replaced. After a few weeks of searching for one (intergalactic back order apparently) I was able to find one and had it shipped overnight. Plugged it in, and voilà, 4high and 4low when I push the buttons.

But here's the problem, I still have no 4wd. The lights come on, and I can feel the torque in 4Low, but if I step on the gas in an inch or two of snow, only the rears spin. My next guess would be the transfer case motor. Is there some kind of click or other sound I should hear from under me when engaging 4WD?

 

[BigRondo]

Did you provide your VIN when you ordered the new 4x4 Control Module?

When replacing the 4x4 Control Module, you must provide your VIN in order to get the correct part. There are several different part numbers and installing the wrong one could lead to other issues. Ask me how I know this :biggthump

I recommend checking all the connections on the the transfer case motor. When my 4x4 lights were flashing, and I had no 4x4, it turned out to be a bad ground on the transfer case motor. I replaced the 4x4 control module and the switch before the bad ground was discovered.

Good luck getting it sorted.

Please keep us posted as feedback helps others reading this post looking for a fix to the same or similar issue!

 

[Squirrels]

I did provide the VIN and was given the updated 4X4CM.

I plugged it in and had all the correct lights light up when selected, but wasn't until I started fish tailing in the snow did I realize something didn't seem right.

I had my wife floor the pedal in an empty snow covered parking lot and noticed only the rear wheels spin in 4Auto, 4High and 4Low.

I tried switching back and forth from low to high several times on the off chance something would be jarred free, but still no luck.

As soon as the snow stops and I get a moment, I'm gonna put the truck up on the ramps and have somebody switch back and forth and see if I can feel anything on the transfer case shift motor or transfer case.

 

[BigRondo]

Be sure to check all wiring connections on the TC motor, especially the ground.

 

[Squirrels]

Update:

So I got under the truck and tapped the transfer case motor while having somebody go back and forth from auto to high to low. I could hear/feel a clicking in the motor. After doing this for 5 minutes, I had my wife floor it in the snow; 3 wheels spun. The rears and the passengers side front.

So now I ask; is that normal?

My understanding is this truck is not equipped with a limited slip or locking differental.

 

[BigRondo]

I believe this is correct. I can do some research tonight when I get home and post up the info.