1983 Jaguar XJ-SFACTORY OEM SERVICE PROCEDURE

Fuel Pump Relay Test

  1. Turn ignition switch "ON". The fuel pump should run for 1-2 seconds and then stop. If pump does not run, or does not stop, further diagnosis is necessary.
  2. Check that inertia switch cut-out button is pressed in. Remove inertia switch cover and attaching screws and check to see that the wiring harness connection is secure. Remove wiring harness connector from switch and check for continuity across switch terminals.
  3. Pull button on inertia switch out and check for an open circuit across switch terminals. Reconnect wiring harness connector and replace switch cover. Reset inertia switch button.
  4. If inertia switch operates to specifications, ground terminal 85 of fuel pump relay and turn ignition switch "ON". Check for battery voltage at terminal 86 of main relay. If battery voltage is not present, check battery supply from ignition switch via inertia switch.
  5. Check for battery voltage at terminal 87 of main relay. If no voltage is present, check for battery voltage across terminal 85 and ground connection of main relay. If voltage is now present, replace main relay.
  6. Check for battery voltage at terminal 86 of pump relay. If no voltage is present, check for an open circuit between terminal 87 of main relay and terminal 86 of pump relay and correct as necessary.
  7. Check for battery voltage at terminal 87 of pump relay. If no voltage is present, check for battery voltage across terminal 85 of pump relay and ground lead. If voltage is now present, replace pump relay.
  8. Check for battery voltage at terminal 30 on both relays and at fuel pump positive terminal. If no voltage exists, check for an open circuit between terminal 87 of pump relay and positive terminal of pump and correct as necessary.
  9. If pump still does not operate, check ground connections or replace pump.
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.