I just removed the A/C compressor in my 95 4.3L and I must say a BIG thanks to this forum because I probably wouldn't have pulled it off without the info I gathered off this site. Since I don't have the funds to fix the compressor itself I put a Bypass Pulley in its place. Fired up the engine and no problems.

But! On my way back home just now the "Service Engine Soon" Light came on. Is that just because the compressor is no longer plugged in or is there something else I should be looking for?

 

The OBD (on board diagnostic) system does not monitor the A/C system. As such, you shouldn't have any problems related to the removal of the compressor.

You really need to get the codes read to know for sure what the problem is.