@Bobbyboy welcome to forum.
is the battery main switch on, if so does it have voltage?
as above states, the impeller in the pump do get seized up and require a spin plus a clean up (WD40 will do this)??
all else fails then the push button module could be at fault here. I've assisted where a little poking and prodding with a multimeter to see if the voltage is present just wasn't going through to the push button and ended being a dry solder joint on the circuit board. cheap fix and lucky too (module can be pricy)
Hope this assists you. Pace.