4 wheel drive problems

[Bagman]

I own a 94 Explorer Limited Edition which I am having trouble with the 4 wheel drive.There is no lights on the switch.When I push the buttons,the truck dosen't go into 4 wheel drive.I had garage check out electrical system and it seems ok except for not lighting up! When I drive, the left front wheel clicks like it's trying to engage but dosen't .We went over the wiring diagrams and can't figure it out.
Any help would be great!
Thanks Bagman

 

[DeRocha]

98% of the time the problem is related to the electronic shift motor on the transfer case. Basically the shift motor is responsible for rotating the transfer case selector shaft from 2H -> 4H -> 4L. If the geared sensor has lost is position and no longer knows what postion it is in it will do nothing as a default mode. The other cause is the electric motor can get bound or frozen and fail to move when given power. I would check out this highly detailed thread on Fixing the Shift motor In the mean time you can try locating the shift motor and gently tapping it with a rubber hammer. This can jar the motor loose and hopefully into working again.

 

[ahhjaws]

Is it a constant clicking at the tire? In that case it would be hubs. But usually if the light is not turning on, then it would be the shift motor.

 

[DeRocha]

There are 2 things going on...1st the shift motor is most likely not working, and 2nd the AutoHubs are ratcheting ... I would bet the hubs make proportionally greater noise with the sharpness of turns. The AutoHubs will make this noise if you have packed them with grease. An over abundance of grease will cause the hubs to become hydrolocked. This will pre-load the hub and cause it to almost try and engage which is where the clicking noise comes from. The HUBS are a dry assembly and only require a thin film of grease to prevent rust. If they are packed with grease you'll need to clean them up.