How do you find the problem if you can't engage the four wheel drive on a 1996 F-150 Ford Extended Cab with dash panel selector push buttons?
I know it sounds too simple but , I have the same problem on my 92. Just crawl under and tap on the 4x4 solenoid with a wrench or small hammer. it's next to the transfer case. I still have to do this every once in a awhile
THERE IS ALSO A FUSE FOR IT SO YOU MAY CHECK FOR IT.
There is possible the switch could be bad or the 4x4 shift module located behind passenger side kick panel. there is a code you cane check for that. write me if you need help on that @ email@example.com or the electric module on the transmission.