OK, The SIMPLE thing to do is this. When it fails, have someone activate the System. Be at the 2 pump solenoids. You are only concerned about the 2nd solenoid with the Pump motor Cable. When activated, does the MOTOR wire have 12 volts? If YES, the Motor is bad. If NO, then that solenoid is bad. LOOK at the 12 volt wire nut on the Pump Motor. Classic OLD age/burned will show melting or black gummy on the plate where the bolt goes into the motor armature. Also, if you can easily wiggle the wire nut at the motor, it is defective. Doug