WITH THE PUMP RUN SWITCH 8501 WIRE FOR THE MASTER RELAY AND 8601 WIRE FOR THE PUMP RELAY DISCONNECTED FROM THE RELAYS, THE 15 AMP FUSE BLOWS WHEN THE PUMP RUN SWITCH IS PUSHED.

IMPORTANT:
PUMP RUN SWITCH ONLY WORKS IN ONE DIRECTION
IGNITION SWITCH MUST BE OFF WHEN TESTING PUMP RUN SWITCH

There is an issue with the pump run switch 8501 wire, the 8601 wire or possibly both. Make sure neither wire is shorted to ground. Fix as necessary.