The Nissan Path

Hi, all:
I have a 1995 SE. It's my THIRD 1995 SE (over many years).
the others have made a sound when locking (chirp!) and unlocking (Chirp!-Chirp!).
This one, doesn't. The door locks work - locking and unlocking - but there is not sound. My manual doesn't seem to address this.
THE QUESTION: Can this sound thing be turned on and off?
Note: I do NOT have an original key fob. I only have after-market fobs. They have multiple buttons and one of the buttons locks/unlocks and another activates the 'panic' sounds. The other two buttons on this fob do nothing.

I'm not sure on the WD21's, but on the later Pathfinders you would press and hold the lock and unlock buttons simultaneously for a few seconds to turn off/on the horn. You might want to make sure the alarm system horn actually works and is connected. Also, check the hood pin switch on the firewall. These were notorious for breaking.

Panic button causes sound to go off, so pretty sure sound is working.
Both buttons pushed has no effect. I've done them simultaneously, with one starting first and the other starting first and held them for up to about 20 seconds. Nothing. Hmmm...

The WD21 alarm systems were a little different because they weren't installed at the factory; rather, they were port installed. This is why you find little to no information in the factory service manual about them. Nissan did release a technical service bulletin which gave wiring diagrams and diagnostic information on the system. There was also a tester for the system (I believe it was made by Kent-Moore) that would plug in place of the theft control unit under the driver's seat and let you manually test the system using toggle switches on the tester.