DCC Fuel pump control kit

[67 caprice]

FPR-35 35A fuel pump Control Kit

Will this work with a FAST EFI?

How does it lower the voltage to the fuel pump at idle, and raise is at full throttle?

Why do you need to connect it to the fan input wires.

[Hammered]

Should work with any EFI system using a TPS.
It's a Pulse Width Modulator and does not lower the voltage. It basically turns the power off and on at a high frequency. At idle you have more off time.
The instructions I found don't show a fan connection. You must be looking at their fan controller.

http://www.dccontrol.com/0820.htm