My selector switch does not light up when engaging four wheel drive on my 98 f150,could this be my GEM module gone bad ?

 

does the transfer case engage or the light on the dash just out?

 

4 x 4 HI you get one light... 4 x 4 LO you get two lights .... what do you see ? what do you feel / hear when you turn the ****.

 

No lights come on at all I've already replaced dashboard switch,I hear no sounds coming from transfer case I do have vacuum at the solenoid switches on firewall

 

Scan it and see what is going on, doubt the gem module is an issue, maybe the motor on transfercase went bad or hubs are not locking, I bet the hubs are not locking

 

I scanned it yesterday nothing other than the typical 171 code

 

I would check voltage at the transfer case motor. Probably need to pull the motor and check operation....... Pull motor, turn the dash ****, and watch what motor does or does not do......You should get that light, and hear the clunk into gear. You don't normally hear the front axle differential engage, and could not tell anyway if the transfer case is not locked in.