While I agree with Chris, the jumper test is just that. A test to see if you need a charge, not a perminant solution to the problem. He is right, in that you don't want to run it that way. Long enough for a test is just fine.

I conducted this test on mine, and would not hesitate to tell someone to jumper it out to find out if you need charge.

This test will tell you you either need a charge, or that the switch is bad. Most likely scenero: you need a charge.

Now, there is also another thing to look at. Behind the glovebox, mounted to your blower motor housing is a relay. If this relay is AFU, spuratic, or missing altogether, your compressor clutch will not engage the compressor.

My relay is black in color, and looks just like the dredded fuel pump relay, except that it has less spade terminals, so they are not interchangable. The reason I say this, is because there is a smaller relay there too.

Hopefully the jumper test will tell you what you want to know.