Subaru Speedometer Glitch Points to Turn Signal Issue

Having moderate experience with car repairs, I faced a similar electrical fault on my 2008 Subaru Legacy diesel last year. The symptoms were nearly identical, with erratic indicator light behavior and speedometer issues. After some troubleshooting, my workshop found the root cause was a faulty cable connection near the turn signal assembly. The repair involved fixing corroded wiring and replacing a damaged connector. Total cost was 95€, including diagnostic time and parts. The automotive lighting system in these Subarus can be tricky, as multiple components are interconnected. What often looks like a simple lamp replacement issue can actually be related to wiring or connector problems. Before suggesting more specific solutions, could you provide: current mileage, whether the issues happen more during wet weather, if any other electrical components are acting up, whether the turn signal problems occur on both sides This information would help determine if your issue matches what I experienced, as these electrical faults can have various causes in different model years.

Thanks for the detailed information. My current mileage is 62387 KM and the last service was done 3 months ago. The electrical fault appears worse during wet conditions, and the signal lamp issues occur mainly on the right side. The radio also occasionally flickers when the turn indicator is activated. I checked the flasher relay by swapping it with a known good unit, but the problem persists. This suggests the issue might be deeper in the wiring harness rather than just a faulty component. Given your repair cost reference of 95€, I might schedule a diagnostic at a specialist who knows these Subaru electrical systems well.

Based on those additional details, your situation sounds nearly identical to what I experienced. The wet weather correlation and radio interference when using the turn signal strongly point to a wiring harness issue, just like in my case. The fact that swapping the flasher relay didnt fix it confirms my suspicion. In my Legacy, moisture was seeping through a damaged grommet near the front right fender, causing corrosion in the wiring harness that affected both the turn indicator and other electrical systems. The broken lens on my turn signal housing was allowing water to reach the bulb contacts and connectors. While bulb replacement seemed like an obvious fix, the real solution required: Replacing the damaged wiring harness section, Installing new waterproof connectors, Sealing the housing properly My final repair costs were: Diagnostic fee: 45€, Parts (harness, connectors): 85€, Labor: 120€ Given your similar symptoms and mileage, I recommend getting the entire automotive lighting system checked, particularly the wiring harness and connections. The total repair might cost slightly more than my initial estimate, but fixing it properly prevents more extensive electrical damage later.

You provided very useful information about the wiring harness issue. My symptoms do match exactly what you described, especially the correlation with wet weather and radio interference when using the turn indicator. The cost breakdown helps me budget for the repair. I will definitely get the entire automotive lighting system inspected, focusing on potential water ingress points and wiring connections. Your explanation about looking beyond a simple bulb replacement makes sense, given the multiple electrical faults I am experiencing. I already scheduled an appointment with a shop that specializes in electrical fault diagnosis. Will have them check the turn signal assembly and surrounding areas for moisture damage. The combined cost of 250€ for diagnosis, parts, and labor seems reasonable considering the complexity of the repair. Really appreciate the detailed explanation about how water infiltration can affect multiple systems. This helped me understand why the electrical problems are interconnected rather than isolated issues.