Seat Formentor lighting system fault

I experienced similar electrical problems with my Seat Ateca. The symptoms you described, namely the erratic headlight switch behavior and the stored error codes, resonate with my past issues. The headlight switch is connected to the car's electrical system through the fuse box. I suggest you check the corresponding fuses to the headlight switch. A faulty fuse may cause intermittent electrical issues. I would recommend inspecting the dimmer switch and its associated wiring harness. Sometimes, a loose connection or a corroded terminal can cause these symptoms.

Can you please clarify which connection you are referring to? Are there specific areas or components I should focus on when inspecting the dimmer switch and wiring harness?

Given the symptoms and the error codes, it is likely that the connection to the headlight switch itself is the problem. I experienced the exact same issue. I ended up taking it to the workshop, as diagnosing electrical gremlins can be time-consuming and requires specialized tools. They were able to pinpoint the faulty connection and repair it quickly. It might be prudent to consult with a qualified technician to avoid any potential damage to the vehicle's electrical system.

I appreciate you sharing your experience. Following your advice, I had my Seat Formentor taken to the workshop. As suspected, the issue was indeed related to a faulty connection in the headlight switch circuit. The repair cost was 95€, which aligns with the preliminary assessment. Thank you once again for your help.