Fuel Pump Relay: Testing and Inspection

Fuel Pump Control Xj-6/Vanden Plas:

FUEL PUMP RELAY

Locate relay in right rear corner of trunk.
Switch on ignition. Pump should run for one to two seconds, then stop.


Note: If pump does not run, or does not stop, check systematically as follows:

Check inertia switch cut-out button is pressed in.
Detach inertia switch cover and ensure both cables are secure.
Pull electrical connectors from switch and check continuity across terminals.
Pull button out and check open circuit.
Remove ohmmeter, replace electrical connectors, re-set button and refit cover.
If inertia switch satisfactory, earth (ground) pump relay terminal 85, switch on ignition and check circuit systematically as detailed below.
a. Check for battery voltage at terminal 86 of main relay. If yes: Proceed to test b. If no: Check battery supply from ignition switch via inertia switch.
b. Check for battery voltage at terminal 87 of main relay. If yes: Proceed to test c. If no: Check for battery voltage at earth (ground) lead and connection from terminal 85 of main relay. If satisfactory renew main relay.
c. Check for battery voltage at terminal 86 of pump relay. if yes: Proceed to test d. If no: Open circuit between terminals 87 of main relay and 86 of pump relay. If satisfactory proceed to test d.
d. Check for battery voltage at terminal 87 of pump relay. If yes: Proceed to test e. If no: Check for battery voltage to earth (ground) lead and connections from terminal 85 of pump relay. lf satisfactory, renew pump relay.
e. Check for battery voltage at supply lead (NS) and connections to fuel pump. If yes: Faulty pump or earth (ground) connections. If no: Open circuit between terminal 87 of pump relay and supply lead connection to fuel pump.