Fault symptom: No heating, no hot wind comes out when the temperature knob is turned on to the maximum. After pressing the AC button for cooling, the cooling effect is very poor, but it can be judged that it is working normally based on the fuel consumption and the throttle sound of the compressor refrigerant. Another phenomenon is that the internal and external circulation damper will automatically open and close, which has a linkage effect with the temperature adjustment knob setting (I am a manual air conditioner), and the inlet and outlet pipes of the heater are also hot.
Based on the phenomenon, we can basically judge that the temperature adjustment server is broken.
I thought it would be easy at first, but after working on it all afternoon, one of the bolts on the server was very difficult to screw and the position space was too small. I don’t know who has a good idea.
This requires removing the guard under the steering wheel. You can take it out by pressing the headlight knob and rotating it.
The decorative board can be directly pried off
The foam from the air conditioner outlet is also removed
The server is exposed. Under an iron plate, there are a total of 3 bolts. The one relying on the server wire socket is difficult to remove
You need to remove the 2 bolts in Figure 3 and the lower bolt in Figure 1 first to make room for the server bolts.
Remove bolts from iron plates
disassembled
Break the iron plate and the brake gang together to make room. I have been screwing the self-tapping bolt in the picture all afternoon.
I used this to remove it
Remove the server, but it’s not stuck, the motor is broken
Position sensor resistance
Test the resistance is very small, apply a 12V voltage, it will show a short circuit
Anyway, it’s broken, take apart the motor and have a look
You can see that there are a total of three brushes, two of which are tilted and one has run to the other side.
The brush cannot be repaired, so we can only replace it. You can buy a motor back cover and replace it. There is an entire stand-alone product, which is the RC307 motor.
The server model is 1KD 907 511D. You can also directly buy a server to replace it. My choice was to repair the motor and buy a back cover. Since it would take a few days to get there and I still need to use the car, I thought that the internal and external circulation damper could be temporarily used and the motor inside could be removed and replaced.
This one has also been repaired.
Remove and remove the motor
Replace it with the temperature adjustment server
Power on and turn it around, and the sensor resistance changes normally
This bolt is really difficult to remove, so I came up with a way to make the fixing place open, put on the bolt first, and then just clamp it directly. When removing, just remove the two bolts below and pull them out directly, which is much more convenient.
Put on the bolts first and then install without taking photos. It’s easier.
After installation, VCDS software is required to set up basic
During sensor calibration, you can see that the servo link drives the damper to fully open and close once.
There will be no trouble codes after that. Start the car and try out hot and cold air and return to normal.
Next, repair the motor, buy the back cover of the 370 motor online, and replace the originally damaged brush. It would be more convenient if you could buy a cheap RC370 motor
Bought it for 5 yuan
With a slight difference, you can use
Install the back cover
For test running with power, the current is slightly high and the rotor is a little tight. You can knock the shaft to make the gap larger. Just turn your hands and make it slippery.
Connecting terminal rotated 90 degrees
Clip in, weld one end
The repair is complete and the truck is ready to be loaded.
Vikifpm 
4 
September 3, 2024 
