Now for the dumb questions. Is it an electric or mechanical gauge? If electric, power on? I just did the same thing recently and primed with a cordless dewalt drill and could feel resistance. You should be able to feel the torque as it pumps. Did you give it enough time to fill the oil filter?
Mechanical gauge... it's definitely not a gauge issue, as when rotating the pump by hand, I can tell that there's no resistance. Either the pump isn't working (perhaps something got destroyed internally) or it is spinning air
When I primed the system back in January, I felt resistance immediately, and the oil filter was certainly filled with oil after the 5+ minutes of priming. I assume that the oil is still in the filter.
