"220V AC Cooling Fan" works, and upon inspection of the car lacks a low speed fan relay (user reflect this car repair shop repaired the other). But will be installed after the cooling fan only high gear without its low gear. After careful examination, found 217 relay burned, resulting in a high-speed cooling fan always running, after replacing the 217 relay, fault disappears. In the process of moving water table shows the temperature is normal, but if stopping the engine idling, the water table, although the display between 90-l00 ℃, but this time the cooling system has been "boil." At this time, found that "220V AC Cooling Fan" can not run. The car cooling fan control, and Audi's control is very different. Samsung car Caravan car cooling fan is controlled via the car computer. After examination, "220V AC Cooling Fan" lack of control relay ground. When the engine is in idle running state, with a thermometer to measure the actual temperature of the coolant has reached 110 ℃, the car can still indicate water temperature between 90-100 ℃. Temperature sensor plug with a multi meter to measure the resistance value of 100 ohms, therefore, initially suspected temperature sensor plug is damaged.