BMW Spool Low Pressure Fuel Pump PWM Activation Harness

The Spool PWM activation harness runs an auxiliary low pressure fuel pump with pulse width modulation through a Hella solid-state relay instead of a standard relay.

Why you need it

Many kits run a Walbro 525 on a traditional relay, which keeps the pump at full voltage the whole time it is on. Brushed pumps do not love 100% duty cycle, and a 525 can pull around 20 to 25 A under heavy load. Running it with PWM cuts brush wear, bearing wear and heat in the tank.

Fits

• BMW low pressure fuel pump kits with a ground-trigger controller such as a Motiv Reflex

What's included

• Spool wiring harness with braided sleeve
• 10/12 AWG Tefzel wire
• Genuine Hella solid-state relay
• Deutsch connector, plus the mating connector to convert a flying lead to plug and play

Good to know

This harness activates on a ground trigger only. If you run a plug-and-play Reflex, disconnect the positive connection. Flying lead Reflex users can use the included mating connector.