T-Roc Electrical Gremlins: Dashboard & Light Switch Chaos

I had almost the exact same issue with my 2020 T-Cross last winter. Having some experience with electrical issues in cars, I first thought it was just a blown fuse. The symptoms were identical, unusual activation of lights, dashboard flickering, and the headlight switch acting unpredictably. The tail lights would sometimes stay on even with the car locked. The automotive switch system was clearly malfunctioning. Took it to the workshop where they diagnosed a faulty connection in the main lighting control wiring harness. The cable connecting to the dimmer switch had developed corrosion at the plug point. The total repair cost was 95€, mostly labor for tracking down and fixing the connection. The fix took about 2 hours and has worked perfectly since then. They also cleared all the stored error codes. Could you share: Have you noticed any correlation with weather conditions? Does the issue happen more when using specific light settings? Are there any warning lights on the dashboard? Did you recently have any electrical work done on the car? This information would help determine if youre dealing with the same root cause or potentially something different in the lighting control system.

Latest service was at 80000km. Thanks for the detailed response. Weather doesnt seem to affect it, but the dashboard lights act up more frequently during nighttime driving. No specific light settings trigger it, it happens out of nowhere. The fuse box has been checked and all fuses are intact. The check engine light occasionally flashes when the automotive switch system acts up. No recent electrical work was done. The car throws error code P0600 when scanned, pointing to a serial communication link malfunction. Interesting that you mention the wiring harness, I did notice some resistance when turning the headlight switch lately. Will have it checked for corrosion at the connection points. Good to know the repair costs were reasonable in your case. Would you recommend trying to clean the connections first, or should I go straight to having the whole wiring checked professionally?

Thanks for the additional details. That P0600 code combined with the switch resistance definitely points to a communication issue, very similar to what I experienced. Given the symptoms you describe, particularly the unusual activation during night driving and dashboard lights acting up, I would strongly advise against DIY cleaning of the connections. When I attempted this on my T-Cross, I actually made things worse and triggered more electrical system errors. The car lighting system in these models uses a complex CAN-bus network. The resistance in your headlight switch suggests the issue might be more extensive than just surface corrosion. In my case, what seemed like a simple connection problem turned out to involve multiple points in the wiring harness. Since youre experiencing the check engine light and error codes, a professional diagnosis would be the safest route. The technicians can properly test the entire circuit and identify if theres damage to the main automotive switch module or just connection issues. One thing to note, the P0600 wasnt present in my case, so your issue might involve both the lighting control module and the serial communication system. This could affect the repair cost, but having it properly diagnosed will save money in the long run. Based on my experience, I recommend getting a full electrical system diagnostic done rather than attempting partial fixes. What started as an intermittent issue with my dashboard lights quickly evolved into a more complex electrical problem.

Your situation seems quite similar but more complex than mine. The check engine light and P0600 code are concerning, especially since they point to a communication link problem. Youre right that attempting a DIY fix could make things worse. Since my electrical problem involved basic corrosion but yours shows signs of deeper issues with the automotive switch system and lighting controls, I should probably take it to a professional. The dashboard lights and unusual activation during night driving definitely suggest something more serious than what you experienced. The resistance in the headlight switch does make me nervous about potential damage to the wiring harness. While your repair was straightforward and cost-effective at 95€, I suspect mine might involve more extensive work given the error codes and multiple affected systems. Ill book it in for a proper electrical diagnostic. Better to address the car lighting system issues properly now than risk more extensive damage. Thanks for sharing your experience, it helped me understand the potential scope of the problem. Would it be OK if I message you after the diagnosis to compare findings?