[XCRN]

I am looking at ways to remove load on the engine of my Jeep while retaining function. I think a good start is going with an electric pump which can be made to work easily. However I want to refine it since most retrofit installs have the pump either off or running 100% which I think will add the load back to the alternator negating gains. I want to be able to vary the amount of voltage based on speeds since I will only need it 90-100% below 25mph and can lower the voltage as speed incrases so cruiseing at highway speeds, the pump will not create load on the motor.

What are options where I can program a PWM output based on a VSS input? I was thinking of using a variable voltage fan controller from a Grand Caravan to regulate voltage to the pump, but I need something to tell it how much voltage to send.