4X4 Not Working

[bjjt30303]

I have researched the threads in various forums as the Moderators urge. There are lots about the problem of 4X4 not working and various solutions, from hitting something with a hammer to something about a switch behind the firewall to a computer issue. None summarize or step-by-step the issue. Can someone do that? In my case, a '91 XLT, when the 4X4 or 4X4 Low Range buttons on the dash are pushed, the indicator lights do not light and the 4WD does not engage. Could just be the switch, I guess. But what is the "chain" for trouble shooting, starting with the switch and on down? Thx.

 

[TPLYNCH]

Do you hear a click from the controller in the rear when you push the button? Generally, it is not the switch or controller. The majority of issues with the 4x4 not turning on is the shift motor. If you don't hear the click, you can test the controller. If the controller passes the test, then you can check the switch or R&R the shift motor. Like said, majority of the times it is the motor, so that's normally where people head next.

 

[DeRocha]

This is the thread you're looking for Shift Motor Rebuild. I would take a rubber mallet and gently tap the side of the motor a few times to see if it will get jarred loose. I needed to do this for the 1st time in over a year during yesterday's Blizzard in New England. A few taps of the mallet did the trip and 4x4 was restored. I think the extreme cold (4 F) was the cause.