Old ERL pump control

[rotrex]

If you talk about the ERL race pump, the third wire activates the pump.
In a 2c set-up, this line is controlled by a pressure switch enabling the pump when line presure drops below its treshhold. This is a autonomous process.
The flow to the jets is controlled by a fast acting or high speed valve through pulse width modulation. This is independent of pump control.

[benstian]

Thanks rotrex