If the manufacturer of your pump is still in business, look 'em up on Google, contact them and ask how to check whether pump is pumping. Most RV pumps are self-priming so that if water is available at inlet, they should pump unless there is a problem inside the pump itself. If you find out that pump needs replacement, check whether your existing wiring, etc., will support a larger capacity pump. There should be a small Intellitec controller device located near the pump which will support a larger, higher amp draw pump.