1995 Ford Bronco Push button 4 wheel drive

I recently tried to put my Bronco into four wheel drive by the push button method and it did not work. The 4x4 light or four low light did not come on when I pushed the button, nor did the automatic locking hubs not work. I attempted to manually lock the hubs and the four wheel drive did not work still. Is there a common reason for this to happen, or is my four wheel drive gone?

Thanks,
demoe200