Glow Plug System
All engines are equipped with pin-type glow plugs which are connected in parallel. The parallel connection allows glow plugs to operate independently of each other and provides 11 volts to each plug during the preglow process. A dual material heating element which consists of a heating coil and a control coil allows the heating process to be 5-7 seconds at 32°F (0°C).
The glow plugs are grounded directly to the cylinder head through the plug body. Each receives separate power directly from preglow time relay (total initial current draw is approximately 200 amperes).
The preglow time relay is located on the left inner fenderwell. The relay is protected by an 80-amp fusible link, mounted outside on the cover of the relay. The relay contains a temperature sensitive resistor which replaces the coolant temperature sensor used with previous relays.
A safety cut-out in the relay turns off glow plug power 20-35 seconds after glow plug light goes off when no attempt has been made to start engine. This keeps battery drain to a minimum and protects glow plugs.
A switch in the relay is triggered if one or more glow plugs fail. This turns off the indicator lamp and signals a need for repair. The indicator will normally come on for at least one second even if engine is warm.