I had a Stanley garage/gate/whatever transmitter that wired to any 12V source. It was all-weather & I had mine wired to my highbeams & hidden behind the upper grill. Pulled up the driveway & flashed my highs & garage door opened or closed. beats having an opener (A/K/A housekey) on your sunvisor looking for a theif & buying batteries all the time. Cool factor was about a 8.

ended up doing the DRL mod & removed the opener. Later replaced the gdoor opener with a Genie intellicode & completely rendered this opener obsolete.

might look on ebay or anywhere Stanley openers are sold for one. the kit had the transmitter that you set dip switches on that matched the dip switches on your existing opener. works with other brands as my old opener was a crapsman.

FWIW.
DAve!