Help with programming 2 remotes for my garage door opener
I have a 1992 sears craftsman garage door opener that i want to program 2 remotes for. The original remote works, but when i use the learn button to program a new remote (61LM Liftmaster), the new one works, but the old remote doesn't. If i clear the programming, and then program the original remote, it works, but the new one won't. Seems like i can't get both to work at the same time.
I was told that i was using 2 different technologies: one old remote and one new remote. This makes sense. So i went and bought another new remote, but still had the same problem: only one would work, and the other wouldn't. It only depended on which one i programmed first.
My question is how do i get BOTH remotes to work?
Garage door opener model # 139 535 15SR
Serial # 1121 D02680