A/C Clutch doesnt turn on

So I went to check my AC and I noticed my clutch is not turning on, I checked the recharge nozzle and very little air came out...My question is, Does there need to be freon in there to turn on the ac clutch or should that run regaurdless?(obviously when the switched is turned to a/c) thanks

There is a low pressure cutoff switch on the accumulator to keep the compressor from burning itself up when there is insufficient freon in the system. You can remove the connector to the cutoff switch and short the two terminals with a paper clip to see if that is the problem. The clutch should engage when you short across the terminals, just don't let it run very long like this...this is only a diagnostic check.
If the clutch doesn't engage, you may have a bad compressor or clutch.
 
Now that I think about it, if you have a voltmeter you should check for 12 volts at the connector at the clutch before you try shorting the cutoff switch connector. If you have 12 volts at the clutch, the cutoff switch isn't the problem and you probably have a bad clutch.