Could really use some help

[fixkick]

its not easy to measure the voltage to any pump, after all its on top,l where only mini mouse can walk.
one way to test it is tank out is a dummy load on the 2 wires,
using a 5 amp load. 2 to 3 ohms resistor (60watts) (or connect an old head lamp there) both beams connected at once.
best is head lamp, test.
put it across the 2 pins, at pump (pump unplugged and out) the measure voltage key on , see 12vdc there, no 5, not 6 not 8 , 12, lowest is 11v) keyon for 3 seconds
see lamp be BRIGHT,
if that passes, then the new pump has chance.
or inspect all 4 connectors end to end on the pink /black wire pair from pump to relay.
no rust,