Beeper is probably failing - located by / under the brake fluid reservoir wrapped in grey foam.

The VX does not really have an alarm that offers much protection. It has a door / overhead light sensor. If you broke the window and climbed in, it would not go off. If you tried to hot wire or even start it without disarming, I do believe it would sound but there is no starter lockout to my knowledge. It may have some memory and flash the LED differently - check to see if when you arm it without having a door completely shut (it does a long solid tone) if it changes the normal flash rate.

As soon as I started adding interior accessories, I added a real alarm to protect them and the vehicle. Remote start was also mandatory living in TX.