Codealarm CA-110 not letting remotes be programmed

Tried many other places, so I thought i'd come here and see if help is found here!

I bought a code alarm CA-110 off of eBay, and it came with 1 remote that was not the original. I set it up on my bench to see if it worked, and when I pushed the buttons on the remote, nothing happened. So I put it in programming mode, and it would not program in, I tried other remotes too and none of them programmed in either.

Does anyone know why this is happening and how I can make it accept my remotes?

Thanks!