joeld wrote:
When you say you can turn the compressor by hand, are you sure the compressor is turning or just the clutch? In order to turn the compressor, the ignition switch must be on and then AC set to on position. This locks the clutch to the compressor.
But regardless, if there is compressor oil on the underside of the hood there is a seal that has failed. Usually this is the shaft seal behind the clutch.

Was this a new replacement compressor or a rebuild?

Joel