a/c clutch will not engage

[1991 supra guy]

Thanks I unplugged and bypassed one of the switches and the clutch engaged making a terrible grinding noise and smoked a bit, also engine ran very rough. The system did not absorb any of the freon, so I shut it off. My thoughts were if freon was low once absorbing a bit would stop the noise. I did not let this run for long before shutting off. Decided to take it to someone with more knowledge but wanted to get a few thoughts here. The switch i bypassed was reinstalled, now when i start the car I get the same noise from the compressor with ac button off. I'd like to remove the ac belt but the adjustment belt pulley does not move only the bolt backs out, any ideas ? I'm sorry this all seems so scattered. I appreciate all responses.