Glow plug, Supplied each

Glow Plugs are critical for starting up a diesel engine.
The pre-heat, starting, and post-glow phases of a glow plug’s operation affect not only the start-up function, but the vehicle’s overall performance as well.

If your vehicle is having problems starting from cold it could be a sign that your glow plugs have passed their best, but before spending out on new plugs investigate all possible starting problems’ could it be the starter motor?, glow plug relay? Fuel?