6.9L - Glow Plug Control System Upgrade (98-4-20)

WAIT LAMP IF 1983 VEHICLE WITH LATCHING AND AFTER GLOW RELAY

1. Locate latching relay under dash (approximately 152mm (6") passenger (right) side of steering column and approximately 51mm (2") right of diesel lights warning module). Reference 1983 Electrical and Vacuum Troubleshooting Manual (EVTM).
2. Using a jumper wire, jump Pin 2 (orange) with Pin 5 (black with pink stripe) (Fig 2 ).
3. Leave remaining pins open (Fig 2 ).

WAIT LAMP If LATE 1983 OR 1984 AND LATER VEHICLE (NO LATCHING RELAY, WAIT LAMP ON EVERY TIME GLOW PLUGS ENERGIZED)

1. Remove blue wire from power relay (right inner fender well) and install it on the electronic module terminal that feeds the glow plugs.
2. Remove blue wire from chassis-mounted power relay and install on engine-mounted control module glow plug feed terminal (Fig 3 ).

AT CHASSIS-MOUNTED POWER RELAY (RIGHT INNER FENDER)

1. Connect power lead (black with yellow dots on early 1983 or red on late 1983 or 1984 and later) on the same post as the glow plug lead wires. This now makes the glow plug lead wires the battery supply for the Solid State System. These are the wires on the two (2) large posts (Fig 4 ).
2. All that the vehicle-mounted power relay is being used for is a junction block. Remove and tape back all other leads. Remember the blue wire on late built 1983 or 1984 and later vehicles was removed in the previous Step (Fig 4 ).

ENGINE-TO-CHASSIS HARNESS CONNECTORS EARLY 1983 VEHICLE WITH LATCHING RELAY

Remove 8-way connector from engine harness supplied with new 7.3L engine. Remove connector on old engine and put the following wires in the appropriate locations (on new solid state wiring harness) (See Fig 5 ).

ENGINE-TO-CHASSIS HARNESS CONNECTORS LATE 1983 OR 1984 AND LATER VEHICLE

Has 8-plug connector already on chassis. From engine harness, remove fuel heater lead and wait-to-start light lead (Fig 6 ).

FUEL HEATER

Tape connector provided with solid state engine harness back into harness and use connector provided in chassis harness.

TEMPERATURE SENDERS

On early 1983 vehicles, they are provided with the chassis harness. Use these and tape leads back into harness.

On late 1983 and 1984 vehicles (eight (8) wire plugs only), all sender wires will be utilized.