jeep Workshop Repair Guides

Jeep Workshop Service and Repair Manuals

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Fuel Pump Ballast Bypass Relay <--> [Fuel Pump Ballast Resistor Relay]|Description and Operation|Page 1848 > < Automatic Shut Down (ASD) Relay <--> [Main Relay (Computer/Fuel System)]|Locations|Page 1843

Cherokee 2WD L4-150 2.5L VIN P MFI (1991)

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Fuel Pump Ballast Bypass Relay: 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.

Fuel Pump Ballast Bypass Relay <--> [Fuel Pump Ballast Resistor Relay]|Description and Operation|Page 1848 > < Automatic Shut Down (ASD) Relay <--> [Main Relay (Computer/Fuel System)]|Locations|Page 1843