Additional info Following a major service including new VW ignition leads replaced because the car (VW Sharan auto 2.8 vr6 1996) was idling roughly, I have found that the water temperature guage rises to over three quaters. The problem now is that the climate control fans do not operate until the water temperature reaches this high point! (ie, heavy queing traffic). Once driving normally the temperature drops to midway and the air con stops (although the buttons and display all work OK. I One other point is that the Sharan is converted into a wheelhome camper van which has a 12volt water heater fitted. This is wired up so it only comes on when the engine is running (via a pair of relays & aux battery) . Since the climate fault the water heater is only working when the climate fans start! It seems a 12v trigger voltage to the water heater has been tapped from the heating system (ecu). My garage state that my engine cooling fan is only running at full speed and they are going to replace the resister unit. The cruise control has also stopped working. Garage states all vaccum system is OK with no leaks so back to electrical fault?! I would appreciate any thoughts on this weird situation.