Anyone know about the connections for the wired switch that operates a (probably) Chamberlain garage door opener? Going to help a friend with some tasks at the w/e and one of the things he'd like to do is install a new bellpush to open the garage door from inside the house. There's a wired switch inside the garage. This has 3 buttons (open/close, light, disable remote) but only single bell wire linking to the unit. So what differentiates the functions (timing of current applied?) / how to replicate just the open function.
Forgive the vagueness but I've not seen this setup yet and want to be prepared / not waste time playing around or stuffing up the unit.
Ta muchly B.