I'm working on a '92 Loyale with a/c.  It seems that any selection I make on the HVAC panel the a/c compressor is always running. I noticed this when I was running the heater and I can hear the compressor pull on the engine.  Is this a feature of this model? I recall some cars would run the a/c compressor during defrost to help dehumidify the air, but not in the heat mode.

That is not normal. My first GL did that. Someone had hacked into the wiring and wired it always on. The compressor was worn out and I had to replace it.

 

The compressor should only be on for ac and defrost. It should cycle on and off when the thermal load is light.