Volvo Repair: 1990 240 Air-conditioning problem..., compressor clutch, air conditioner

Question
I have no AC. The clutch doesn't engage. I jumped the wire to the compressor clutch directly to the battery, and it clicked into place like a new one. I checked for voltage at the thermostat-knob-switch thing in the dashboard, and found something odd. There are two green wires right next to each other, and two other wires, and all four of them had power (with the ignition switch and all the air conditioner controls turned on, but the engine not running). That doesn't seem quite right, but on the other hand, there seems to be power going through that control. What do you think? Thanks.

Answer
Joe, possibly the a/c relay.  When the key is turned on is when you should have power there.  Did you check the refrigerant level?  If will not come on if it has no refrigerant in the system.  you can try the by pass trick at the reciever/dryer.  run the car and just touch the 2 wires together.  Look at the wires under the airmass meter to see if one came off. Roger