Ignition Ballast Resistor: Description and Operation

Ballast Bypass Relay:

Under any operating condition, except wide open throttle, the fuel pump gets voltage from the fuel pump relay via the fuel pump ballast resistor. When the vehicle is under a wide open throttle condition, the ballast bypass relay gets grounded (ENERGIZED) by the engine controller. When the ballast bypass relay gets ENERGIZED, voltage bypasses the fuel pump ballast resistor and full system voltage is applied to the fuel pump.

Voltage to the ballast bypass relay is supplied through the fuel pump relay. The ballast bypass relay is located on a bracket connected to the power distribution center.