AC Heater Blower for Audi A6 C4

Hello fellow DIY enthusiasts,
I had my air conditioning system refilled last week, and it went well, except that the condenser failed after only one day!
After filling, there was a hissing sound (for about 5 seconds) in the area of the vaporizer, and I asked a Bosch employee what that was. He said that it was normal for this model.

The subsequent functional test revealed that air was exiting the nozzles at a temperature of 0 degrees Celsius.
Before the exam, the instructor said that if the temperature reached 6-10 degrees Celsius, that would be acceptable.

The fact is that my heating fan is no longer working properly.
The blower is regulating the speed uncontrollably, sometimes high, sometimes low, sometimes not at all, and is no longer reaching its maximum performance (speed).

Now, ask me what the error or the cause of this defect might be.
Could the evaporator or something else have been damaged during the filling of the system?

During the second visit to Bosch, only the capacitor, pipes, and compressor were checked for leaks, but not the evaporator. It was then discovered that the evaporator is leaking (using a leak detector).

How do I get my blower working again?

Vehicle: Audi A6 TDI C4, year 1995, Avant (station wagon).

Please help!
Best regards, Bastianna.

Hey everyone,

Does anyone have a helpful answer for me?

Best regards, Bastianna.

0°C is very low; according to the repair manual, the climate should reach 3-6°C. It's possible that the specified operating conditions were not exactly met. Regardless, the climate system seems to be working again now.

"It's probably a faulty blower motor regulator, but I don't see any connection between that and the air conditioning repair."
Check the blower motor voltage using the diagnostic tool (VAG-COM group . The actual value should not deviate from the target value by more than 0.5V.
The blower motor regulator is located in the water tank on the passenger side of your vehicle, near the evaporator housing.

It's also possible that the carbon brushes in the blower motor are worn out.
It provides information, among other things, about strange (to say the least, gruesome) noises coming from the blower unit.
If the blower motor is acting up again, and a firm knock or kick to the glove compartment (which is where the culprit is located, at least in the Audi 80) provides a temporary fix, then it's almost certainly the carbon brushes.
A replacement blower fan from Audi costs between €150 and €350, depending on the model, but a set of carbon brushes from a Bosch service center for €4.10 will also do the job .

Best regards,
Nitrofreak.

Thank you for your responses!
wolfi_b:
The air conditioning system is not working because the condenser (which was identified as leaking during the second visit by a Bosch technician using a lamp) is leaking. Therefore, the system is empty.
This hissing sound from/on the vaporizer surprised me, and now my fan is acting up.
Could it be that the blower control/or something else was damaged?
Unfortunately, I don't have a VAG-COM.
Nitrofreak:
I doubt it's the carbon brushes, but I will check the voltage at the blower connection cable. That way, I'll be able to see if there are different voltage levels.

What now?
Best regards, Bastianna.