95 Explorer 4x4 Not Engaging

I have a 95 Explorer Sport. The button on the dash clicks but the 4 wheel drive is not engaging. The anti-lock brakes are pulsating on their own sometimes too. I am not sure if this is related since it could be the GEM? Can anyone help?

My hubby has a 91 expl 4x4 5spd w/the same prob. He was told it may be the electronic shift motor. good luck!

Tap on the small motor next to your transfer case while having someone else push the 4x4 button. If the problem is the electric motor that engages the 4x4, it may engage it. I had this problem on my 93 Explorer and I replaced the motor with one I got from a junk yard for around 25.00. It has been working for about 2 years now.