I have a 1993 ford bronco with a push button control and when I push on the button to activate the 4x4 I hear a clicking sound coming from the electronic control module andthe transfer case does not go into 4x4. I did a self check on the control module and it said it was good. What else can be wrong and how do I check it. I have a Borg-Warner 13-56 transfer case, the truck had automatic hubs and now it has manual hubs

 

It could be the motor in the transfer case or a bad solenoid to engage the front differential. If you have someone who can drive the truck while you are able to look underneath it, put it in 4WD and roll forward. If the front drive shaft is spinning, then the solenoid needs cleaning or replacing. If it doesn't spin, then the electric motor is possibly bad. Try unhooking the battery for a while and see if it will respond before replacing anything.