While your plumbing may now be non-standard, there are a couple possible explanations..
1. The faucets open and close to allow draining of water pipes for winterization.. Could either be that faucet upstream or dowstream of pump is closed and preventing water flow.
2. Pump runs on 12V
sytems, and possible that battery is problem, or 12V
fuse (separate from 110V AC fuses) is missing or blown.
3. If pump sounds like it is turning and piston is moving, then problem most likely either lack of water flowing inot pump from tank, or that valve is closed blocking flow..
4. If pump cycles on and off quickly and frequently, that is usually symptom of pressure leak somewhere in piping, which will become water leak once water flowing in pipes.
5. If there is power to pump (check for voltage at pump terminals) and no sounds or activity, then pump may indeed be dead or frozen, and in need of replacement...