help with ancient viper alarm

[Guest Halcyon]

I have a Viper car alarm, probably around 10 years old. I don't know the model number, and I don't have the manual. Just recently, it has begun showing the following symptoms.

It no longer chirps at all when I arm or disarm the alarm via my remote (2 button).

I can not get the alarm to go off when I give my car a significant shove.

The panic feature still works.

The doors still lock and unlock when I use my remote.

With the doors shut, the light remains a solid red, instead of blinking.

When I open the doors, the light goes off and remains off.

So my questions are: How do I determine the model of my alarm? I have taken the dash apart, partly, and the alarm unit says, "Viper 800+", but I can't find any information on that particular model (possibly due to its age?). I read in one of the other posts on here that it might be stuck in Valet mode, and I tried the suggested remedy of lock/unlock/lock with door open to no avail.

Any help would be appreciated. Thanks a lot.

[wndotint]

Turn the key on, press the valet switch and let go. The light should go off.