1994 PCED OBDI-A | SECTION 20A: Diesel Diagnosis—7.3L IDI Engine |
The Solid-State Glow Plug System consists of the glow plug controller, the glow plug harness assembly and glow plugs (Figures 17 and 18).
The system determines the glow plug temperature by electronically measuring the resistance of the glow plugs. It then maintains this temperature regardless of ambient temperatures.
The system is actuated when the ignition switch is turned to the RUN position. The "WAIT TO START" indicator lights until the glow plugs reach the proper temperature. The indicator goes out and the engine can be started.
The afterglow operation of the glow plugs continues after the "WAIT TO START" indicator turns off. The glow plugs cycle on and off for a period of time. This helps to reduce white smoke after engine start-up.
The glow plug system can be recycled by turning the ignition off and on. This immediately restarts the glow plug cycle. The engine can be started as soon as the "WAIT TO START" indicator goes off.
The power relay is mounted on top of the solid-state controller circuit board. The complete assembly is mounted on the right rocker cover (Figure 19).
The system uses positive temperature coefficient (PTC) glow plugs. The resistance of the glow plugs changes as the temperature rises. The glow plugs use bullet-type terminals (Figure 20).
Use the electrical wiring schematic (Figure 21) when diagnosing the glow plug system.
