The alarm stopped arming on our 98 JGC. When using the remote door lock, it would always chirp the horn and arm, and red light on the dash would flash. Now it just locks the door without the chirp or the alarm.
Any help would be appreciated..

do the interior lights go off immediately when you lock it with the remote?it might be a problem with it thinking that a door is still open or one of the lock cylinder disarm switches.other than that i would say check all the fuses to start.

No they do not. They stay on for approx 20 secs. Previously when arming with the remote the horn would chirp each time it was pressed, now alll I hear is the door locks

Is there a valet switch on your security system?

There is a remote setting that changes these functions, you might have turned off your audibles by accident, I'm not sure how to turn them back on on your model, but it usually is by holding the arm and disarm at the same time, or just the disarm for a few seconds. Try that, if it doesn't work, consult the dealer, they will usually walk you thru it at no charge. Let me know if it works, Later

Have no idea about the valet switch, where would it be?? I have tried the lock/unlock button at the same to no avail, unless there is some secret combination to doing it

Do you have a dealer near by? I would talk to them. I don't think factory alarms have a valet switch. It's mostly aftermarket ones that do. They are on the "brain" of the alarm if it does have one.

My 99 JGC exhibited a similar problem... No alarm arming, no interior lights until the key was inserted into the ignition...

The underhood light was burned our and the respective fuse was also blown. After replacing them everything has worked fine since.

I suggest checking for a burned out kight bulb and their respective fuses...