Glow Plugs
Glow plugs are small 6-volt heaters operated by the electronic controller/glow plug relay assembly. Assembly is located at rear of left cylinder head.
Glow plugs cycle on and off, powered by 12 volts to give rapid heating. Glow plug light on dash should illuminate as plugs cycle on and off. Glow plugs cycle for approximately 25 seconds with ignition on, whether engine starts or not.
On and off cycling varies with system voltage and temperature. A glow plug inhibit switch opens above 125°F (52°C) to prevent glow plug operation. Switch is mounted on coolant crossover passage, at front of engine.