VW Sharan Starter Struggles Despite Clean Battery

My 2009 VW Touran 2.0 TDI had nearly identical symptoms. The charging system showed similar behavior, weak cranking and voltage dropping significantly during start attempts. After checking the starter motor and finding it functioning normally, the main issue was traced to a failing ignition switch that wasnt properly engaging. This created resistance in the power supply circuit, causing the voltage drop during cranking. The problem required: Full electrical diagnostic scan, Testing the charging system under load, Inspecting fuse box connections, Replacing the ignition switch assembly While not a majorly complex repair, leaving it unfixed risks complete starting failure. The diminished power delivery can also strain other electrical components over time. The symptoms you describe strongly point to either the ignition switch or charging system rather than just a battery issue, especially since it runs fine after starting. Having the complete electrical system tested would identify the exact cause rather than just replacing parts. I recommend getting this checked soon since the fault tends to worsen gradually until the car fails to start completely. The diagnostic process needs specialized equipment to properly test voltage drops under load.

Thanks for the detailed reply about the ignition switch issue. Your troubleshooting steps make a lot of sense given the electrical fault symptoms I described. Can you share how much the complete fix ended up costing? Also curious if you experienced any other short circuit problems since getting it repaired? Just want to make sure I budget correctly and check all the potential issues while its at the shop. The starter motor still works but that voltage drop during cranking has me worried about causing damage to other components. Looking to get this sorted before it leaves me stranded somewhere.

After getting the electrical fault properly diagnosed, it turned out the Terminal 30 continuous plus circuit was indeed causing the voltage drop issues. The mechanic found the wiring harness had some deterioration which was creating resistance in the power supply. The complete repair came to 290€ including parts and labor to fix the heavily discharged battery system. Since having it fixed, the starting has been consistently strong with normal voltage readings during cranking. No short circuit issues or other electrical problems have surfaced in the months since the repair. The mechanic also inspected the entire circuit breaker system and charging components while doing the work. This thorough check was worth it for peace of mind, as degraded electrical connections can cascade into bigger problems if left unchecked. The original starter motor was actually fine, it just wasnt getting proper power due to the faulty circuit. Getting the complete electrical diagnosis likely saved money in the long run by identifying the true cause rather than replacing good parts unnecessarily.

Finally got the car checked out at the repair shop. The mechanic found exactly what you mentioned, it was the ignition switch causing problems with the power supply. They did a full electrical diagnostic scan which showed voltage drops during starting. The repair involved: Replacing the faulty ignition switch, Cleaning all power connections, Testing the starter motor, Checking the entire charging system Total cost came to 340€ including parts and labor. Pretty reasonable considering the thorough electrical fault check they did. The starter now engages strongly every time with normal voltage readings. Real relief to have it fixed before getting stranded somewhere. The mechanic mentioned the old ignition switch had quite a bit of wear that was disrupting the power flow. Everything has been working perfectly for the past few weeks, no more multiple attempts needed to start the engine. Thanks again for pointing me in the right direction with the diagnosis. Saved me from needlessly replacing the starter motor when the real issue was in the ignition circuit.