Four wheel drive does not engage.

didn't specify S or K series...S series, look under battery for vac diaphragm and verify operation

Check the lever if is connected to the gearbox

Had the same problem. Mine turned out to be the decoder motor.

Sounds like you have a bad switch.

check fuses should b a 4wd fuse refrence your owners manual. if not problem try removing batt connectors pos and neg. resetting computer. sometimes transfercase gets jammed.

there is a sensor on the tranny or transfer case that may have gone out check this and you may have a quick fix

It is Torque On Demand. When you are stopped there is no need for the front end to be engaged, no demand. Once you start moving, the lights should begin working as the demand for four wheel drive engagement increases, if the conditions require four wheel drive. It's the way the system works. Enjoy!

could be your front actuator or your actuator motor on the transfer case.

the transfer case is sticking from non use, change the lube in the case ( Ford ATF) and drive it for awhile it should be ok then.

Hello;
Sounds like yoou have a short either in the switch pod or in the 4wd electrics. Check for pinched wires or bare wires grounding out at the front axle and at the transfer case.
Thanks;
Rich
RPM Northwest