Hi my glow plug light dose not stay on for any length of time it go's straight out. New plugs fitted so now I'm guessing it could be the coolant temp sensor. I've read there's 2 sensors and one controls if the plugs come on or not via the water temp. I went to vw and they tell me my car only has 1 coolant temp sensor and it's a green 4 wire one dose this sensor control the glow plugs on my gt tdi pd150 engine the car is a 53 reg