Outback Tail Light Glitch Linked to Loose Dimmer Switch

Dealt with nearly identical symptoms on a 2017 Forester diesel last winter. The unusual light activation and dashboard lights error pointed to a failing dimmer switch assembly, which also controlled the tail light circuits. The loose feeling when turning the switch was a clear indicator. While checking the fuse box is always a good first step, this type of issue typically stems from worn internal contacts in the light switch module. The dimmer switch deteriorates over time, causing intermittent connections that trigger phantom activation and error codes. The repair required replacing the complete switch assembly since individual components are not serviceable. It was a serious electrical issue that could have led to complete lighting system failure if left unaddressed. The dashboard lights and tail lights are part of critical safety systems, so this definitely needs professional diagnosis at a garage. The symptoms worsened quickly in my case, went from occasional flickers to complete system malfunction within weeks. Would strongly recommend having it checked soon, as electrical issues tend to cascade when ignored. Not a fuse box problem in most cases when multiple lighting circuits are affected simultaneously with error codes present. This sounds exactly like the faulty switch assembly scenario I experienced.

Thanks for sharing your experience. Your diagnosis matches my situation perfectly, everything you described with the dimmer switch and unusual tail light activation is exactly what I am seeing. Before I book a garage visit, would you recall roughly how much the switch assembly replacement cost you? Also curious if any other electrical gremlins showed up after fixing the main issue? I checked the fuse box first but like you mentioned, with multiple lighting circuits acting up and the loose automotive switch, it seems more serious. The tail lights turning on by themselves is particularly concerning since it could drain the battery if left overnight.

Thanks for asking about the repair costs. I took care of the electrical problem last week at my regular garage, and the faulty light switch issue was completely resolved. The mechanic confirmed it was indeed the switch assembly causing the unusual tail light activation. The final repair bill came to 95€, which covered fixing a poor cable connection in the headlight switch module. No other electrical issues appeared since the repair. The dimmer switch now has proper resistance when turning, and the dashboard error codes have disappeared completely. Looking back, taking it to the garage was the right call, they found the exact connection point that was causing the intermittent lighting problems. The tail lights no longer activate out of nowhere, and all lighting circuits are working as they should. A professional diagnosis was worth it since they could properly test the entire car lighting system to ensure no other components were affected. Much better than risking further electrical complications or battery drain from malfunctioning lights.

The mechanic visit turned out well, took it in yesterday and they diagnosed the exact issue you mentioned. The dimmer switch assembly was failing, causing those unusual tail light activations and error codes. Total repair came to 280€ for parts and labor. They replaced the complete headlight switch module since the old one had worn internal contacts. The dashboard lights are now working perfectly and the dimmer switch feels solid when turning, no more loose feeling. The mechanic showed me the old switch assembly and you could actually see the corroded connections that were causing the intermittent problems. Good call on getting it checked quickly, they mentioned the electrical system could have developed more serious issues if left unfixed. No other electrical gremlins have appeared since the repair. The tail lights stay off unless commanded on, and all the error codes are gone. Definitely worth the garage visit rather than trying to troubleshoot electrical issues myself. Thanks again for helping identify the root cause.