Seat Leon Diesel Air Conditioning Problem

I had a similar issue with my previous Volvo V70. The symptoms you describe point towards a defective blower motor or possibly the fan speed controller. Have you checked the relevant fuses? A blown fuse could also cause the heater fan to stop working. Accessing the blower motor can be a bit tricky depending on the car's design. In my Volvo, it was located behind the glove compartment. The HVAC system relies on this blower to provide air flow, so its failure is quite noticeable. Diagnosing the root cause is crucial before replacing parts.

Thanks for the info. I did check the fuses, and they seem to be fine. Regarding the fan speed controller, is there a way to test it, or is it something that usually gets replaced along with the blower motor?

In my experience, it is difficult to definitively test the fan speed controller without specialized equipment. While it's possible to test for continuity or voltage, a faulty controller can still exhibit intermittent behavior. Given the error code and the complete lack of blower function, replacing the blower motor first is a logical step. If the problem persists after that, then the fan speed controller should be investigated. However, I would advise a visit to a workshop for professional diagnosis.

Took the Leon to the workshop. As suspected, the blower motor was indeed faulty. They replaced it, and the air conditioning is now working perfectly. Total cost was 365€, including labor. Thanks for the input.