I've installed a new battery in my '93 Mazda 626. Car starts up great now.

For some reason, my remote door locks/starter is no longer functioning. When
I "flash" the hood pin the parking lights blink normally. When I press Start
or Lock/Unlock nothing happens at all - no click, etc. I've tried the
programming steps as if it were a new remote, but at the point where you hit
a button for it to learn, nothing happens. The battery in the remote is less
than a week old, so should be fine.

I've disconnected the battery again to try and reset the unit with no luck.
I've removed and reinstalled the battery in the remote as well. Next is a
fresh battery then checking fuses and relays.

Anyone have any idea where I should start looking?

Unit is a ProStart CT-3400 TW. Starter cutout and horn not installed.

Thx!