88 300zx A/C issue

Just after fixing a power steering leak, my compressor stopped turning on. I press the a/c button and it lights up like it should, but no draw on the engine, nothing from the compressor. Something happens when I press the button, as I hear a slight change in the air blowing into the car (it sounds like its blowing stronger?) but nothing from the compressor. One thing is that I had two vacuum hoses disconnected for a week and didnt know it (resulting in fail safe - air coming only from defrost vent, but my compressor still turned on then). However those are reconnected, everything worked until I fixed my power steering leak, im almost positive I didn't knock anything out of place, so how can I find out my problem, hopefully without buying a guage. And how do I test my compressor if the button won't turn it on?

Or at least someone tell me where the low pressure switch is on the 88 300zx, so I can bypass it and see if in fact it is just low on freon (its been two years since my last charge).