Wiring – Network Garage Door opener/ how does the switch work


I'm trying to connect a relay/switch to a Garage door(Lift Master). I know that there are two wires to trigger the garage door. I'm not sure how it works exactly. I'm trying to control the garage door remotely (greater than 1 mile).

How do you trigger the door to open with the wires only?

How do you trigger the door to close with the wires only?

Is there any risks to shorting the two wires together?

Best Answer

Do you have a button switch on the wall to open - close? There are usually two wires going to that. I don't think it will hurt to short those wires momentarily to test it. If it did, Lift Master would get a lot of returns because I'm certain many people have shorted the wired pair upon installation. My Craftsman has two wires going to a multiple switch panel. I can open - close the door, turn on-off the opener light, and lock the remote controls. These functions are controlled by adding a resistance to the wired pair. each control has a different resistance. The open-close is just a short. the unit remembers what direction it went the time before. IE: if you short once to open the door, then short again will close the door.