Shenzhen Fu Sheng Electric co.,LTD
ADD：No。1,Block3,Hongchang,Shunchang Street,Pinghu,Longgang District,Shenzhen China
When the vehicle is in use, the engine will generate too much heat. In order to prevent the engine from overheating and can not work properly, people have designed a cooling liquid circulation cooling system, and the cooling fan plays an important role. For electric cooling fan, the models used in the control methods are not the same, the following combination of two fault examples to understand the operation of two common electronic fan control methods and troubleshooting.
Example 1 An Audi V62.4L displacement car, the car does not turn the electronic fan cooling system due to "open pot", and open the air conditioning when the electronic fan still does not work. This Audi car radiator fan control, through the dual temperature thermal switch control fan relay ground wire to achieve. The car's cooling fan system has two electronic fans, the wiring harness for the red line is the positive line, the brown line for the ground line, the red positive line on the right side of the beam on a positive post fixed.
The red positive line control is divided into fan low-speed relay, air-conditioning relay and fan high-speed relay control. In the maintenance of their attention to their specific location, the fan low-speed relay in the engine on the right side of the fuse box in the third relay position, fan speed relay installed in the driver's sub-fuse box No. 217 relay while the fan low, high speed Operation is through the radiator on the dual temperature thermostatic switch according to the coolant temperature, control relay ground to achieve.
When the air conditioner switch is turned on, the cooling fan is rotated by controlling the fan low speed relay through the air conditioning fan relay. 217 relay grounding wire connected with the dual temperature thermostatic switch, once the coolant temperature rose to a certain temperature, dual temperature thermostat control the relay grounding, cooling fan will enter high-speed operation. In addition, the 217 main relay and the main line of fire when the ignition switch is turned 阌 mechanical strength?
According to the car cooling fan system works, the investigation of the car lack of a low-speed fan relay. However, after it is installed, the cooling fan only has a high-speed gear and no low-speed gear. After careful examination, it was found 217 relay burned, leading to the cooling fan is always in high-speed operation, the 217 relay replacement, the fault disappears. Example 2 A Samsung Jetwing car showed a normal temperature while driving, but if the engine was idling while parked, the water temperature indicator showed between 90 and 100 ° C, and the cooling system was "boiled" at this time. At this time, I found the cooling fan can not operate at all. The car cooling fan control, and the control of the Audi car is very different. This Samsung Jetstar car cooling fan is controlled by the car computer. After inspection, the cooling fan relay is missing control ground. When the engine is running at idle, the actual temperature of the coolant measured by the thermometer has reached 110 ° C, and the water temperature meter of the car still indicates between 90-100 ° C. Use a multimeter to measure the resistance of the water temperature sensor plug is about 100 ohms, therefore, the initial suspect water temperature sensor plug damage.
In the absence of a replacement case, find a 2k ohm slide variable resistance and water temperature sensor plug in parallel to reduce the resistance。 If this time to adjust the sliding variable resistor, so that the water temperature shows the actual temperature of the coolant and the same temperature, the cooling fan actually with the normal operation of the temperature rise。
It seems the reason for the fault is the water temperature sensor plug. As the water temperature sensor plug is damaged, it always gives the car computer a low-temperature error signal that can not make the cooling fan operate, and the cooling fan can not operate normally. Finally, the water temperature sensor plug replacement, the car returned to normal.
Visible, the car's computer receives water temperature sensor plug input signal, when the water temperature reaches the specified value, the computer will control the fan relay grounding, so that cooling fan operation。 These are two very different ways of controlling things, but as long as we figure out how they work and carefully examine and analyze them, we can solve the problem quickly!