[RWebb]

put an addl. temp. wire to get voltage at the terminals for the pump; make sure it works; good time to clean the filter too

But you will have to check each point from battery thru switch to pump terminals - I might bet on the switch...

disconnect battery for safety and wire a small 9V "transistor" batter in to check for voltage - it has so little amperage you cannot do much harm

I see a lot of gunk in the last pic in that connector so take them apart & clean carefully