Subaru Starter Struggles: Bad Terminal 30 Circuit Fix

As someone with moderate experience working on cars, I had a very similar issue with my 2006 Subaru R1. The symptoms you describe match exactly what I experienced, slow cranking and intermittent starting problems. After a voltage drop test showed inconsistent readings, my mechanic found that the main power cable between the battery and starter motor had deteriorated. The charging system was working correctly, but the damaged cable was causing resistance in the circuit. The repair involved: Complete circuit testing, Replacement of the main power cable, Cleaning all ground connections, Testing the starter motor functionality Total cost was 290€ including parts and labor. The car has been running perfectly since then. To help diagnose your specific case, could you provide: any warning lights on the dashboard? Does the problem occur more frequently in wet conditions? Have you noticed any electrical issues with other systems? What voltage reading do you get at the battery while cranking? The terminal 30 circuit you mentioned could definitely be the culprit, but without proper testing its hard to pinpoint if its a wiring issue or potential starter motor failure. A qualified mechanic should perform a complete electrical fault diagnosis to trace the exact problem.

Thanks for the detailed explanation. In my case (48342 KM), I also noticed dimming headlights during starting attempts. The fuse box inspection shows no obvious issues, but the voltage drop test revealed fluctuating readings across the circuit breaker. The power supply seems particularly weak when attempting consecutive starts. No warning lights appear on the dash, and the problem occurs regardless of weather conditions. Battery voltage drops to 10.2V while cranking, which seems quite low despite the new battery. The local shop quoted 380€ for a complete electrical diagnostic and potential starter replacement. Before proceeding, I want to verify if this pricing sounds reasonable for this type of electrical fault diagnosis.

Thanks for those additional details about your R2. Those voltage readings are definitely concerning. When my R1 showed similar symptoms with voltage dropping to 10.4V during cranking, the ignition switch was actually the secondary culprit alongside the cable issue. The circuit breaker was showing correct readings, but poor contact at the ignition switch connection was creating additional resistance. The 380€ quote sounds reasonable considering the diagnostic complexity. My total repair ended up slightly lower at 290€, but prices can vary based on what components need replacement. The starter motor itself typically costs 180-250€ if replacement is needed. Quick tip from my experience: Have them check the voltage drop across each major connection point in the power supply path, especially: Battery terminals to starter motor, Ignition switch contacts, Main ground connections The dimming headlights combined with that low cranking voltage strongly points to excessive resistance somewhere in the main power circuit, similar to what I experienced. Getting a proper diagnosis will save money in the long run rather than just replacing parts. Would you mind sharing what the voltage readings are at the starter motor terminals during cranking? This would help confirm if the issue is before or after the starter in the circuit.

Thanks for suggesting those voltage tests. I checked the starter motor terminals during cranking and got readings between 8.9V and 9.4V, which confirms a significant voltage drop in the circuit. After inspecting the electrical fault more closely, I noticed corrosion around one of the main power supply cables near the fuse box. A secondary voltage test at various points revealed the worst drop occurring between the circuit breaker and the starter motor connection. Given these readings and your experience with similar symptoms, I will proceed with the 380€ diagnostic and repair. The price seems fair considering the detailed testing required to properly trace an electrical fault like this. Will have them focus on checking all the connection points you mentioned, especially around the corroded area I found. The starter motor itself still sounds healthy when it does turn, so hopefully just addressing the power delivery issues will resolve the problem without needing a full starter replacement.