Truck air compressor diagnosis help needed

stuart, Feb 3, 10:45am
Just bought another old TK bedford as a farm truck.
Its been powered with a nissan engine.
However it appears the air compressor is not working, my worker got the truck engine going and so far I have only had time to look at the compressor and see the shaft from the diesel injector pump is rotating.
I have had no experience with these pumps and looking for tips.
I thought I would take off the main steel pipe from head of pump for starters, and wind it over or start it up.