I have a 2002 and had a issue with the internal pressure valve failing; check out this video, describing this problem. NOTE: i was able to do the valve repair WITHOUT, removing the compressor and everything worked out for me.
I did this repair and it fixed mine.
Another common issue to check; is the blend door bushing, breaks and it causes it to stick.
Those, would be good to check; a set of pressure gauges, can help diagnose the problem and many auto parts stores, will rent you a set for free. After, 22 years, the compressor, could be toast but it could be the internal valve or the blend door bushing as well.