Well it appears that my buzzer is broken. I open up the unit and applied 12 volts directly to the buzzer and got just a little vibration. Interstingly enough the unit needs to be plugged in for the "Engine" light to work. Seatbelt light doesn't work but it's tied to the buzzer.
I searched all the major parts guys (Parts America, Rock Auto, AC Delco) and found nothing.
Any ideas?
Thanks
Paul