Suzuki Splash Starting Issues Traced to Power Supply

Having some experience with electrical issues, I faced almost the exact same problem with my 2012 Suzuki Swift last winter. The symptoms match perfectly what you are describing. After checking the fuse box and finding no visible issues, I had the charging system thoroughly tested at a workshop. It turned out the battery was severely discharged and showing signs of internal damage. The workshop also detected minor corrosion on the wiring harness connections near the battery terminals. The complete diagnosis and repair included: Battery load test, Checking the ignition switch functionality, Testing alternator output, Cleaning battery terminals and connections, Replacing the battery Total cost was 290€ including parts and labor. Since the repair, starting has been consistently strong with no issues. Before suggesting more specific solutions, could you share: How old is your current battery? Do you notice any electrical issues like dim lights or slow power windows? Has the check engine light appeared? Do you make mostly short trips or longer drives? This information would help determine if your situation matches what I experienced and allow for more targeted advice.

My battery is only 14 months old and I recently completed the 55000 KM service. After inspecting further, I found the starter motor terminals had significant corrosion and the wiring harness connecting to the ignition switch showed signs of wear. The power supply seems inconsistent when testing with a multimeter, showing voltage fluctuations. Getting the starter motor connections cleaned and checking the electrical fault codes might be a good next step before replacing any major components. Does anyone have experience with testing the wiring harness on these Splash models specifically?

Thanks for the additional details about your Suzuki Splash. When I had similar voltage fluctuations on my own Splash, cleaning the starter motor terminals alone wasnt enough to fix the issue. After inspecting my wiring harness more thoroughly, I found that the voltage drop was actually caused by a short circuit in the wiring connecting the ignition switch to the starter motor. The insulation had worn through at a point where the harness bent near the firewall, causing intermittent connection issues. My repair involved: Cleaning and protecting starter motor terminals, Replacing the damaged section of wiring harness, Installing new connectors at the ignition switch, Testing voltage at multiple points in the circuit Total repair cost was 180€ and resolved both the voltage fluctuations and starting issues completely. Given the similarities in our symptoms and the age of our vehicles, I recommend having your wiring harness thoroughly tested, particularly around any bend points where wear is more likely to occur. The power supply inconsistency you measured with your multimeter strongly suggests a wiring issue rather than a component failure. Testing the complete circuit from battery to starter motor, including all ground connections, would be the most reliable way to pinpoint the exact location of the voltage drop.

Thanks for sharing those repair details. Based on your experience, I'll focus on the wiring harness inspection, particularly around those bend points near the firewall. The voltage fluctuations I'm seeing definitely match what you described with your short circuit issue. I've scheduled a diagnostic session at a workshop tomorrow to properly test the circuit breaker and all power supply connections. They'll do a complete voltage drop test from the battery through to the starter motor. Given the corrosion I found and the inconsistent multimeter readings, a wiring harness fault seems increasingly likely. The 180€ repair cost you mentioned is much more reasonable than I feared, especially compared to replacing major components. I'll update the forum once I get the test results and know exactly what caused the power delivery problems. Hoping it's just damaged wiring that can be replaced rather than a more serious electrical fault.