First I have to ask why you think you lost freon? If you lost enough for the "low pressure" switch to open, then you need to make a repair.

Charged cans of freon will go in a low system without it running - slow but it will go in. Holding the can upside down so liquid goes in will work until the clutch engages. If you put two cans in and the clutch still does not cycle, chances are you have a different problem.

You really need to invest in a cheap set of gauges if you plan to do some occasional AC work. I have worked on many AC systems, just not had to mess with my Crossfire to give you exact details.

If the system is completely empty, not just low, you really need to pump (vacuum) the system down to remove any moisture/humidity. Refill with the correct amount of oil and freon.

Chances are that the PCM or BCM is controlling the AC clutch (relay) depending on the pressure readings it is getting. I would not suggest jumping any 12v to anything without studying a wiring schematic/diagram.

As for the blower on most cars, usually "high" runs on a relay to give the blower motor full voltage. Any speed below that runs through a module or resistor block to slow the motor down to the desired speed. Again, sorry I can't give exact details for the Crossfire.

Maybe someone else can chime in with more details.

James