Hello, installing a brushless fuel pump and just have a question. Coming from the fuel pump controller, there is a PWM wire which from my understanding is used to regulate speed of the fuel pump. The wires going to the fuel pump are a ground, power, and two signal wires for fuel level and empty tank. So my question is, where do I connect the PWM wire?

 

The PWM wire would go to the output pin of a standalone ECU, so the ECU could request low pump flow at low load and high pump flow at high load. Check your ECU's software or instructions to see which of the outputs can send a PWM / Duty cycle signal.

 

It looks like there are 3 wires between the pump and controller, red, black, yellow. Is that how the pump is set up? If yes, then you need a 3rd pin to get to the pump.

 

If this is the kind of pump you have, then you likely need a different bulkhead connector for the extra yellow wire or steal the wire from the low fuel light.

 

that’s very similar to the pump I have, it did come with a bulk head connector, I just didn’t picture it or mention it. So from what I’m understanding there are no stock wires to connect to the pwm wire, and my choices are to either ground it or connect to the ecu? (Running haltech 2500)

 

The Haltech should have a pwm output. If grounded, it will run full speed all the time and unnecessarily heating the fuel.

Jack

 

That was gonna be my next question is if I should just ground it or put the effort into running an extra wire for the pwm. Also in a side note, it didn’t come with anything to mount to the hanger so I used the rubber sleeve from the old pump, and the a hose clamp, do you think there’s any possibility of over heating issues or anything with the rubber sleeve around it?