This summer my A/C started to go out on my 98 1500 4x2 5.2L (still blowing, just not blowing cold at all). After using the recharging kit did not work, I took it in to the auto hobby shop and me and the mechanic did some electrical/sensor troubleshooting with Alldata and the service manual; discovered that the signal to activate the compressor clutch was being transmitted but the clutch was not engaging (the coil was not shorted or open either). Since none of the parts stores sold the clutch separately and the dealer wanted more for a clutch than a new compressor, I decided not to tear out and replace the compressor since I had been managing fine driving with the windows open, etc.

Starting a month or 2 ago whenever the engine is <1100 RPM or so a repetitive squeak can be heard from under the hood varying in speed with the RPM. The noise seems to be coming from the A/C compressor - is this something that is going to spectacularly fail or can I keep driving it and just not using A/C?

 

If you aren't going to replace the compressor I would get a shorter belt and by pass it. I did that for a few years before I fixed the A/C in mine.

 

Depending upon the temperature where you are right now, the compressor may not engage. Below 60*F system won't run. If you're in a warmer climate and above these temps. try this: (you may have to wait till summer weather returns though)
turn on the a/c system and if the compressor does NOT engage, tap lightly on the clutch pully with a hammer or some other tool. Lightly! you're not trying to cream it and be aware that the belt and pully is moving. If it engages, the washers on the hub need to be adjusted to close the gap.
As far as noise/squeak, forums are not good places to diagnose such things as one man's squeak is another man's grind...or something like that. Anyway, try a squirt of WD-40 at the pully hub and see if that solves the noise, albeit temporarily. If so, then your clutch is going south. It is replaceable. Search all local auto parts places or on-line sources. However, special clutch tools are required to R&R so an a/c shop may be your best solution.
WC