How to program your 1995, 1996, and 1997 Mercury Mountaineer remote keyless entry fob alarm by yourself at home without going to the dealer.

Turn ignition from OFF to RUN (as far as you can go without cranking the engine) 5 times within 10 seconds, with the 5th time ending in RUN.
All doors will lock then unlock to confirm programming mode.
Within 20 seconds, press any button on 1st remote transmitter.
Door locks will cycle to confirm programming.
Within 20 seconds, press any button on 2nd transmitter (up to 4 transmitters total possible).
Turn ignition to OFF.
Locks will again cycle to indicate end of programming mode.