Garage door wall switch

[Greg Miller]

I'm moving into a new house, and the previous owners took the garage door wall switch with them and there's just two wires coming out of the wall.  Connecting them together operates the door as normal.  Even though most garage door wall boxes only have two wires, they usually have three buttons, one to open/close the door, one for the light, and one for the lock.  Has anybody figured out how the light and lock buttons work?  The brand of mine is "Legacy", but I'd imagine they're all pretty similar.

[Tim VanSant]

If you're going to use a "universal" replacement switch, just double check the compatibility with your model of opener and it should be fine.

To answer your question though, I believe that the light and lock buttons use resistors and/or diodes to alter the voltage/current. The logic board in the opener then handles those functions. I think the open/close function just shorts the wires together.