98 Blazer AC question

With the summer season approaching, it came to my notice that the AC is not functioning as it should. The blower and refrigerant are fine, but the air coming out the vents is tepid.
Observances show that the compressor does not activate. I tried bypassing the pressure switch (?) over by the refrigerant container to see if it was faulty but the compressor still failed to engage.

Question is, I recently had the water pump replaced. Does this procedure involve the AC system in any way? I.E. Can a module or switch be disconnected?
What areas should I look into for to see if the compressor has failed? Can low refrigerant cause the compressor to not kick in? (I could be reading the level wrong)

The refrigerant has never been changed, so it is the original factory install. (8 years old)

How do you know the refrigerant is fine?

Did you pressure test it?

With a 8 year old charge, the refrigerant being low would have the compressor not coming on.

You are correct, I should have more concrete info. Thanks for the quick reply! This forum is an well run operation and most helpful. I was glad to see the windshield wiper issue being discussed. I suffered from that a two years ago and paid $150 bucks to fix it. At least there is a solution posted now. Bye and bye, there is a recall on that, but only up to '97 models.