38 RC pickup, carb issue in Mopar Flathead Truck Forum Posted May 12, 2018 · Report reply 1 hour ago, Jerry Roberts said: Relays are used for things that draw a lot of amps like headlights or dual horns . You won't need a relay for the electric fuel pump . Thanks Jerry. Does it matter how I wire the fuel pump? Most of what I’m reading says it will pump in the correct direction no matter how it is wired up.