Folks usually disconnect the alarm controller because one of the lock switches is bad, as in my 91 300SE. Each lock has a switch in the lock and unlock extreme key positions. The controller doesn't distinguish one switch from the other. In my case, only the lock side switch works. The alarm is armed when I lock the car from the driver's door. When I unlock the driver's door, I pull the door open, then quickly turn the key to the lock position. That turns off the alarm. I got tired of doing that so I disconnected the alarm again.

AFAIK, those switches aren't available separately. You have to get the whole latch assembly to get new switches.

Sixto
91 300SE
87 300SDL