Most unlikely. Glow plugs simply preheat to allow the engine to turn over from cold.
bad glow plugs or faulty glow plug timer module
IIRC, the 5.9 Liter Cummins uses a glow grid, not glow plugs. It is mounted right in the intake line after the turbo charger. Disconnect it, turn the key on, and see if it gets hot. Jim
Diesel Models: Normally a problem with faulty glow plugs. The starter motor will appear to turn normally. Its possible that not all the glow plugs are faulty, and after several attempts the engine will start.
You may be refering to the glow plugs. They help the engine turn on.
If your car is a Diesel engine and when you turn the key on it ignites the glow plugs because diesel gas can congeal (become thick) in cold weather. So the glow plugs warm the diesel and turn it back to a more liquid state.
Your glow plugs are not heating up. You may have bad glow plugs or relay. try turning on the key ( this should start the warming of the plugs and a light on the dash will come on letting you know it is ok to start if not the relay is bad) if no luck turn off the key and let it cycle again. if it is still difficult to start you may need new glow plugs.
It takes a lot of amps to heat the glow plugs and turn over a motor with such high compression at the same time.
Do you have an old diesel or a new one? If you have an old diesel engine, you turn the key to the "run" position and look for the glow plug light. Glow plugs heat the cylinders, and when the engine is warm the light goes out, you turn the key and the engine starts. On a new diesel, you turn the key and it starts.
Kia Sedona 2.0 CRDI does not have glow plugs. It does not have glow plugs it uses compression to start. It might be the heater box? You can try priming the fuel before you turn it over by squeezing the baloon in the front of the engine compartment when you squeeze it it pushes the fuel up for starting.This worked for me but the fault code showed it was the fuel pump. It wasn't it turned out to be a leaking injector. Needed to change 2 then it starts fine now. It was not the fuel pump at all.
If only the ignition was on with no other appliances running you may be lucky. But the glow plugs in summer are not that critical. It could well be that there will be insufficient power to turn the engine over
I note the relay (part No NCL100040) is called an "ignition and glow plug heater relay". The 75 will usually start if you turn the key before the glow plugs have heated, therefore the glow plugs are probably only needed for cold starts. Glow plugs are not needed when a diesel engine is hot. The "ignition" reference may mean that some other circuit is controlled by this relay (obviously there is no conventional ignition as it is a diesel). FYI The part is also used on the Range Rover TD6 post 2002 An internet search suggest the cam sensor can cause starting problems and fault codes similar to a faulty glow plug relay.