My 2002 Ford ranger will not go into 4x4. When I turn the switch it doesn't do anything. I have had problems in cold weather it not going in until it got good and warm but it always went in. Any clues on what this might be? Vacuum line, module, switch, or transfer case (lets hope not)??

Thanks

 

Definitely check fuse, if its not that just go down the line,grounding, switch, wiring harness, etc

Usually this stuff is something simple.

(by the way, you wouldnt happen to live near georgia or tennessee a buddy of mine recently sold a red, extended cab, 4.0l ranger, his 4wd didnt work before he sold it and he told me he fixed it but he may have not)

 

Welcome to the forum

It will be an electrical issue, no vacuum involved on a 2002.

Go here and get your owners manual: https://www.ranger-forums.com/genera...1-models-3747/

Check out the fuses for 4WD, the shift motor fuse #13, in engine fuse box, 20amp would be the first one to check.
And if it was slow shifting cold then motor may have been drawing close to maximum amps, if so fuse could have finally blown
In cab fuse box check #5 and #10

Buttons/***** won't be the problem, never even read about 4WD buttons not working
When you turn on the key the 4WD lights should come on and go off, that is a BULB TEST, not 4WD test, it just shows that bulbs are connected to power and not burned out

Common issue with shift motor is that the motor brushes lose contact with armature(part that spins) so motor stops working.
Tap on the motor a few times and try to shift it into 4WD
If it starts to work again then you will need to rebuild or replace the motor, because it will just get worse over time and disuse.
To prevent this from happening again you should shift into 4hi then 4low then back to 2WD once a month, you don't have to move the truck, just shift it in the driveway.
This keeps the brushes and armature clean and working.

4x4 modules did fail, last resort is to swap it out, no way to really test these, wrecking yard if possible, not new