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The operation of the glow plug control device.

Model: (Various brands) Various
Part: Glow plugs

In this tutorial video, see how the glow plug control device works: the pre-heating system with glow plugs is equipped with a control device and consists of the plugs, the control device, a relay for the plug, etc. The control device is located on the instrument panel and indicates when the plugs are heating; it contains a resistor connected to the same power source. Normally, this control device should glow about 15-20 seconds after turning off the key. It is important to know that prolonged heating of the plugs can damage the control device. The plugs are connected in parallel, so if one plug shorts out, the control device will glow more quickly; conversely, if the plug is disconnected, the control device will take longer to glow.

Updated on 18 August 2026 by ScegliAuto

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