Audi S3 No-Start: Check Solenoid & Wiring First

Had similar symptoms with a 2017 Audi S4. The car would not start despite having good battery voltage. After troubleshooting, found the starter solenoid was failing intermittently, causing inconsistent power supply to the starter motor. The ignition switch was engaging, but the starter solenoid was not receiving proper signal. It turned out the relay switch wiring harness had deteriorated insulation causing intermittent connection issues. The repair required replacing both the starter solenoid assembly and the associated wiring harness section. Common failure points to check on these engines: Connection between starter solenoid and power supply, Ignition switch signal wire integrity, Ground strap condition, Relay switch mounting points for corrosion This was a serious issue requiring specialized diagnostic equipment to properly identify. The starting problems got progressively worse over time before complete failure. Would recommend having the entire starting circuit professionally tested, as visual inspection alone may not reveal the underlying electrical fault. A comprehensive starting system diagnostic is essential here, as these symptoms often indicate multiple worn components rather than a single point of failure.

Thanks for sharing your experience with the starter solenoid issue. After replacing the wiring harness and solenoid, my car wont start issues were completely resolved. I checked the voltage drop across connections and all readings are now normal. Also found a blown fuse in the main fuse box during the repair that needed replacement. Did you track the total repair cost for the parts and labor? Just curious if any other electrical gremlins surfaced since fixing the starter circuit? Would be helpful to know what to watch out for.

Since fixing my starter solenoid and wiring harness issues, everything has worked flawlessly. My total repair costs came to 410 Euro for parts and labor, but recently I had to address an unrelated Terminal 15 ignition positive interruption that was causing intermittent starting problems. That was a simple 95 Euro fix involving a faulty cable connection. The circuit break detection system caught this new issue early, preventing any major problems. Regular voltage checks across the starting system have shown consistent readings since both repairs. The wiring harness replacement really solved the core issue, and the starter relay switch has been operating perfectly. A tip for ongoing maintenance: keep an eye on voltage readings at startup. Even small variations can indicate developing issues with the electrical system. The relay switch connections especially need periodic inspection for corrosion or loose fits. Based on my experience, once the main starting components are properly repaired, subsequent electrical issues tend to be minor and easily addressed before becoming serious problems.

Good to hear you guys had similar experiences. After all the headache, I finally got it sorted at a specialized Audi shop. The total repair came to 380 Euro, definitely less than I expected after reading about others experiences. The mechanic found the wiring harness was damaged near the starter solenoid, causing intermittent voltage drop issues. They also discovered and fixed a loose battery terminal connection I hadnt noticed during my initial checks. The power supply is now steady and the car starts perfectly every time. The shop did a full diagnostic scan afterward to ensure no other electrical issues were present. Interesting to hear about that Terminal 15 issue, will keep an eye on the starting performance just in case. For now though, pretty relieved to have this fixed without any major complications. Thanks for helping point me in the right direction with the relay switch and wiring harness check suggestions.