POLARIS RANGER 570 Wont Start

Fuel Pump Assembly

The fuel pump is an integrated unit containing the motor, filter, and pressure regulator. A humming sound without engine ignition indicates the motor is energized but the internal regulator has failed or the pump is cavitating, failing to provide the specific 58 PSI required for the EFI system to fire the injectors. Replacing the entire assembly ensures the pressure regulator and filter are renewed, which are the most common points of pressure loss.

SKU: 2521307

EFI Power Relay

If the 'humming' is actually a high-pitched buzz or chatter, the EFI relay is failing to maintain a solid contact. This prevents the fuel pump from receiving consistent current, causing it to cycle rapidly or run at sub-optimal RPMs. This is a common failure point in Polaris Ranger models caused by moisture ingress or pitted contacts within the relay housing.

Main Wiring Harness Ground Terminal

The fuel pump and EFI relay rely on a clean ground path to the chassis; corrosion at the terminal block (located under the seat or front hood) creates high resistance. This resistance can cause the fuel pump to hum loudly as it struggles with low voltage, or cause the EFI relay to cycle rapidly, preventing the engine from starting due to insufficient fuel pressure or ECU power.