So I have an old Marantec garage door opener and an outdoor wall keypad (40 HZ) that quit working. After searching on the internet I found that you cannot buy keypads anymore as they are too old and not compatible. So I thought of hardwiring a keyed switch to the unit, but it needs to be a momentary contact which probably doesn't exist, (ie Keyed switch with a separate button) Anyone have any ideas other than me going and buying a whole new door opener. thanks in advance