This job is a pool and spa. Starting from the pump there is an electronic valve that tees. The left side runs the two pool skimmers and pool main drain. Right side runs spa skimmer ans spa main drains. All plumbing tested and the pump runs fine but when you open the valve for the spa skimmer it loses its prime instantly.

If you plugged the valve for the pressure test maybe the valve is leaking. The o-ring on the valve stem that is going to the actuator might be bad.

The valve was tested. I induced water from the pump.

Another thing that confuses me is the pump will be running off pool main drain, pool skimmer, spa main drain but when the spa skimmer valve is opened loses prime. This would indicate massive amount of air from skimmer but it holds pressure. I also tested at the top of the threads to rule out male adaptor. Need help guys!

Is it possible that the spa skimmer weir is stuck in the up position? This would cause the symptom you described. Also, is the spa full enough to be able to run the skimmer?
Just a couple of thoughts.

Is it possible a check valve could be hiding the leak? is the pool actually loosing water? Maybe try isolating the spa skimmer line and pressure it from the skimmer end.Good ideas ChuckGeo the weir thing just happened to me yesterday. It's possible that the leak only opens up under suction not pressure.

i have seen lines plugged up with debris, chestnuts, acorns and DE. No flow of water can be establish from the skimmer to the pump. it wil hold pressure, but its not a crack, its an obstruction causing it

Trackerm makes a very good point. I have had that happen! Also, make sure that you aren't covering the leak with your test plug. I've had that happen a few times, including just last week.

Collapsed flex line can do that to.

Strip the valve and check the seals, pressure can keep the seals seated but suction can draw air.

small leaks around unions that are pulling air back into the system. nobody seems to replace o rings or pump gasket. i have seen cracks in the pump housing that did not leak, shut the pump off and watch the water shoot out of the plastic housing.