Fiat 124 blower motor defective

I have a Fiat 124 as well, although I'm not sure about the year, and I remember facing a similar problem with the air circulation system. It turned out that there was a defective connection in the electrical wiring going to the blower motor. The fan speed controller can also cause this. I'm no expert, but did you try testing the blower motor directly, bypassing the car's electrical system? It’s like checking if a light bulb is dead by plugging it into another lamp.

Thanks for the quick reply! That's a good idea to test the motor directly. How involved was checking the wiring harness and speed controller? Do you have to tear apart half the dash to get at everything, or is it relatively accessible?

Unfortunately, it was quite involved on my car, requiring disassembly of parts of the dashboard to get proper access. Considering you also have an error code stored, and given the mileage, my recommendation would be to take it to a workshop equipped to diagnose HVAC systems correctly. It is similar to having a persistent cough, you can try home remedies, but a doctor might be needed to get to the root cause.

Alright, thanks for the advice! Sounds like a trip to the shop is the best bet. Just got it back from the shop, the blower motor was defective. Total cost was 365€ parts and labor.