In 2008, the cooling fan started abnormally for a long time. I forgot when it started. I only remember going to a friend’s store several times last year, and the diagnostic instrument could not find any malfunction. Because the water tank drain pipe is cold when the fan turns long, it has been working on the water temperature. Later, a variety of online information, began to suspect that it was a circuit fault, because every time the fan turned long. The idle speed will rise by 1000. In fact, this phenomenon is not surprising, it can be understood that fans need more electricity to start, so the computer controls the engine to increase its speed and generate more electricity. Then I was afraid that when the car was old, it would be bad for the engine to get in touch with the wire on the body, so I added an engine to the wire on the body, but it still didn’t work.
After careful observation, it seems that every time the idle speed rises first, and then the fan starts. That’s not right. Then every time I drive, I pay attention to this phenomenon, and then I find that every time the fan turns long, it seems to happen at night, so it’s almost close to the truth!
One day, the multimeter was used to measure the voltage of the generator and battery. first, there was no voltage drop, and the second engine to battery negative resistance was very small, and there was no voltage drop. Then turn on the headlight voltage stable 14.4V, turn on the blower voltage or stabilize 14.4V. Suddenly the fan started and there was no obvious fluctuation in the voltage at this time. A joy in my heart, does it have anything to do with headlights and blowers? These two are the biggest energy users in the car. Then turn off the headlights and the blower alone, and found that the fan started after turning on the headlights for more than ten seconds. Oh, my God! I’ve been working on it for so long, but it’s the headlights!
Two low light bulbs were purchased in TB in March 2021, look at the record of my post that the fan long turn also began in 2021, the specific date can not be remembered clearly, today on the way back from work to refuel to find a brighter place from the trunk to take out the original car halogen lamp changed before to try, it turned out to be really good. Well, it’s something to congratulate on. Finally found the fault before the fan broke down.
Because of this malfunction in the past two years, I have made a lot of things by guessing and relying on the cases found on the Internet.
Change the water temperature sensor at the engine outlet, no
Change the plug wire harness of the engine outlet water temperature sensor, no
Change the water temperature sensor at the outlet of the water tank, no
Clean the air flow sensor. No.
After changing the thermostat, no.
Thermostat punch, no
Change the antifreeze, blow the heat tank with compressed air, no
Add wire from the engine to the car body, no
About so many, did not spend much money about 150 yuan, but the heart is tired.

The next time you drive to remove the installed rail line, and then observe it a few more times, if there is no further failure, then the problem will be solved. If you want to use a LED lamp, you need a power resistor, but it should not be necessary.