Let me take a try at this. My 2000 Sailfish 272 has a GROCO system. The level probe consists of three different length wires with floating float switches on each. The three floats represent Green, Yellow, and Red on the display panel. The panel has a power toggle switch, a pump-out button, and the three lights positioned vertically and a fuse holder. Prior to buying a new panel or pump, try the following:
1. Check fuse( 10 or 20 amp?) A blown fuse usually means that the pump shaft is seized by corrosion, ect.
2. If level indicator lights come on, there is power to the pump.
3. Disconnect pump DC leads and apply 12V from battery or jump battery directly to the pump. If the pump runs, problem is probable switch or wiring.
4. If pump does not run with 12V, remove pump and check that shaft turns freely. If not, place box end wrench on shaft end bolt and move back and forth until smooth. Test pump again with with 12V. I'll bet it operates properly then. I do this work on my work bench, not in the boat.
5. Remember, the overboard pumpout feature does not depend in any way on the float switches or level indications
6. The pumps are very durable and work very well considering the environment the pump lives in.
Hope this helps.
SilverLining