You don't want your lift pump running when the engine isn't. Adding this PPE Dual Relay set and diode is perfect for those times when you have the key is in the accessory or run position (like when you're listening to the radio). With the PPE Dual Relay Set, the fuel pump begins operating only when the starter motor is activated with the ignition key in the on position and continues to pump fuel only while the engine is running. You don't have to worry about any "deadhead" pumping of fuel with this setup. It's easy to install and comes with detailed instructions.