There will be a cooling fan in the car. This is to cool the motor so as not to overheat too much, which will cause the car to crash. However, if the noise of the cooling fan is too loud when the car is running, it will not only make people very distressed, but also cause some damage to the car. Now let's talk about the impact of excessive noise of the car cooling fan from the AC cooling fan editor!

When the electronic cooling fan is running, it will produce excessive noise, which is caused by aging of components or poor dynamic balance of fan blades. It is decided to replace the electronic cooling fan. Fault phenomenon: According to the driver, when sitting in the cab during the refrigeration of the automatic air conditioning electronic control system, you can hear the "whine" noise of the electronic cooling fan when it is running, which is loud and annoying. Troubleshooting: The electronic cooling fan configured for this vehicle is a stepless speed regulating cooling fan.

The AC cooling fan first confirms the fault symptoms, starts the engine, presses the AC button on the automatic air conditioning control panel, the air conditioning compressor runs, and the air from each outlet of the dashboard is cool enough, indicating that the air conditioning compressor works normally. The electronic cooling fan in front of the condenser starts to run. With the increase of the speed of the electronic cooling fan, the noise gradually increases and can be heard clearly when sitting in the cab. It can be seen from the maintenance experience that the new electronic cooling fan is installed and tested. After the engine runs for 10 minutes, the new electronic cooling fan emits a "whine" noise again. The fault symptoms have not been improved. Connect the GTl tester for self diagnosis, select the 7-series E38 chassis model, double-click the item "IHKA Automatic Constant Temperature Air Conditioning" in the main menu of electronic control system diagnosis, and the GTl tester will quickly scan the item. After that, click the "Control Module Function" button, select the IHKA electronic control system, query the fault information, and no fault code is stored.

The AC cooling fan tests the performance of the new electronic cooling fan. The method is as follows: turn off the ignition switch, turn on the ignition switch, select the test item "Electronic cooling fan" in the "Component control" function menu of the GTl310 tester, click the "Activate" button, and the new electronic cooling fan starts to run from low speed to high speed. Stop after 30s. After repeated tests, it is determined that the new electronic cooling fan has good performance, because there is no running noise of the previous type in the whole test process. Exit the "component control" function menu, restart the engine, select the "diagnostic response" function menu, and then view the new working data of the electronic cooling fan. Click the "Display" button again, and the GTl detector will display the new working data of the electronic cooling fan.

The air volume and air pressure stated in the AC cooling fan cooling fan product are the maximum values under ideal conditions, that is, the air volume under the condition of no pressure difference between the fan inlet and outlet (maximum air volume), and the fan blowing to the closed air chamber until the air volume is zero, the difference between the air chamber and the outside air pressure (maximum static pressure). They are not two isolated performance indicators, but restrict each other. The relationship between them is the typical relationship between velocity and pressure in fluid mechanics - the air volume decreases with the increase of pressure difference (specifically, the air resistance of the radiator). The degree of mutual restriction between them depends on the shape of the fan blade and the overall structure design.

The air volume is controlled by adjusting the air nozzle and auxiliary fan, and the corresponding values of air flow and air pressure difference are recorded. Finally, in addition to recording the maximum air volume and maximum static pressure (i.e., nominal air pressure), the pressure flow diagram (i.e., fan characteristic curve diagram, PQ diagram) is generally drawn, Comprehensively show the working performance of a fan under various pressure differences (specifically, the wind resistance of the radiator).