Originally Posted by FreedomDream
Turn on the pump switch and with your volt/ohm meter check the voltage at the pump. If 0 volts then you have a blown fuse. If you have in the neighborhood of 12 volts, and the pump is still not working, the pump motor has probably seized and the thermal protection is bad. Pump needs to be replaced. Not a difficult job.
Having 12v present doesn't mean pump is shot. Typically a controller is in the circuit. Switches connect to controller, controller supplies ground to the pump motor. 12v is always present, only the ground is switched.
Short the black ground lead from the motor to ground, if pump starts controller is bad. I made up a jumper to run the pump in case of controller failure. Connect ground going to controller and negative lead to pump together.