My factory system runs but the compressor clutch does not engage. All contacts checked. How do I diagnose if the compressor is actually bad. I already filled up with Freon but still no go. Thanks.

If the clutch doesn't engage then the system doesn't work.
You can unplug the connector at the dryer and jumper it and the clutch should engage. Also with the engine OFF try turning the clutch by hand...it should be kind of hard to turn but it will turn...this will verify that is isn't locked up.

Think I am making some headway. I put a meter on the green wire and no power going to the compressor when the car and air is on. Where does the power feed from. There is a relay on the side of the blower firewall unit that I already replaced and another on the firewall itself that I will be replacing in a day or two when the replacement relay comes in. Is one of these relays responsible for powering the compressor?