The engine can't seem to manage idle properly when the A/C compressor kicks in. If sitting at idle, I turn on A/C there is a slight drop in RPM, then it recovers and does fine. When driving, down-shifting the manual tranny to stop at a stoplight or stop sign, the idle control seems non-existent and the RPMs drop to ZERO and stalls. This is not safe when turning 90 degrees in the middle of an intersection and the power steering ceases to exist!! The engine idles fine without the A/C turned on.

Is there some sort of sensor that tells the computer to up the RPMs to accommodate the A/C? If so, where is it?

Thanks,
Michael

Most likely you need to clean your idle stabilizer valve. I haven't worked on a 96, but the idle stabilizer acts as a throttle bypass. It will either be integrated with the throttle valve or mounted near and connected to both sides of it.