Trax Starter Issues: Terminal 30 Power Supply Mystery

Had the exact same problem with my 2012 Chevy Cruze diesel. I've got some experience working on diesel engines and electrical systems. First off, even though your battery tests fine, mine showed the same but was actually heavily discharged internally. The starter motor symptoms match perfectly. What really threw me off was that the charging system readings looked normal too. After testing the ignition switch and power supply connections, my workshop found the battery was the culprit despite showing okay on basic tests. They did a proper load test which revealed the real issue. The battery couldn't maintain voltage under high-current demand from the starter motor. Cost me 290 for diagnostics and a new battery, but it fixed the problem completely. No more starting issues since then. Before jumping to conclusions though, what battery brand/age do you have? Also, when exactly does it struggle most, cold starts or when the engine's warm? Could help narrow things down. Would check the battery terminals too, sometimes corrosion can fake these symptoms. Let me know these details and I can share more specific advice.

Just had my 33605 KM service done where they diagnosed a voltage drop between the battery and starter motor. The mechanics traced it through the wiring harness and found corroded connections at a junction near the fuse box. There was a short circuit developing that was causing intermittent power loss. Got the wiring cleaned up and secured properly with new connectors. The starting issues completely cleared up after fixing those bad connections. Total repair was much cheaper than replacing the starter. Worth checking your terminal connections thoroughly before assuming it's a major component failure.

Thanks for sharing the outcome, really helpful to know the wiring was the culprit. Had nearly identical voltage drop issues on my Cruze at around 35000 KM. The circuit breaker connections near the main wiring harness got corroded just like yours, causing those frustrating intermittent starting problems. What's interesting is how the voltage drop symptoms can mimic a bad starter motor or weak battery. The diagnostic showed the same pattern, power loss between battery and starter. My mechanic found the corrosion had actually spread further along the wiring harness than initially visible. One thing I learned was checking the voltage drop across different points in the starting circuit really helps pinpoint these issues. My readings showed nearly 2V drop across what should've been a solid connection, major red flag that led straight to those corroded spots. Quick tip: after fixing the connections, coat them with dielectric grease. Been running perfectly for 2 years since the repair with no more starting troubles. Much better than jumping straight to replacing expensive parts like the starter motor or ignition switch.

Thanks for that detailed info about the electrical fault fix. The voltage drop diagnosis really saved me time and money. I'm glad I didn't rush to replace the starter motor before checking the wiring harness thoroughly. Those corroded connections near the fuse box were definitely the smoking gun. Since fixing the power supply issues and cleaning up those connections, my Trax starts perfectly every time. Total repair was around €150 including parts and labor, way cheaper than a new starter would have been. The dielectric grease tip is solid, already applied it to help prevent future corrosion. The charging system now shows steady voltage readings and the starter gets full power. Definitely learned to check all the connections in the starting circuit before assuming major components are bad. These electrical faults can be tricky to diagnose but often have simple fixes once you track down the real problem.