How to test the 4 wires of a fuel pump?
1 Answers
Automotive fuel pumps typically have four wires, with two slightly thinner ones being the fuel gauge wires and the thicker ones being the fuel pump wires. Connect the thicker wire to ground on one end and insert the other end into the wire terminal. When starting the motor, the wire that lights up the test pen is the live wire, and the other one is the ground wire.