If you have the Essex (1701 or 1704) there is a programming button for the outside door control (the button is the one behind the magazine rack) ,and their is a second box under the dash which also has a programming button which is for the key chain remotes.
If you have the Trimark system, then I can't help.
So, do the buttons light up? That would determine if you have power to the unit (or if it is defective).