VW Sharan No-Start: Terminal 15 Power Supply Issue

I had a similar issue with my VW Touran diesel from 2005. Having moderate experience with car electronics, I first suspected a voltage drop problem when the car wouldn't start. After basic checks of the fuse box and battery connections, I took it to my regular workshop. The mechanic found that the ignition switch wiring had worn out, causing intermittent power supply issues to Terminal 15. A thorough diagnostic revealed damaged cable insulation and a loose plug connection near the steering column. The fix involved replacing the affected wiring section and securing the connection properly. Total cost was 95€ including diagnostic and labor. Since then, no starting issues have occurred. To better assist with your Sharan issue, could you share: Does the instrument cluster light up when turning the key? Are you getting any clicking sounds from the relay switch area? What specific error code is showing on the diagnostic tool? Have you noticed any electrical issues before this complete failure? These details would help determine if your problem matches what I experienced with my Touran.

Last serviced at 55239km, and after reading about your power supply troubles, I agree it sounds very similar to what I experienced. The starter solenoid began working intermittently before the car wouldn't start completely. In my case, the diagnostic showed P0682, indicating a Terminal 15 circuit malfunction. The instrument cluster would light up briefly but then go dark. The mechanic found corrosion at the ignition switch connector causing the power interruption. Key observations in my situation: Battery tested fine, No clicking from the starter, Fuse box inspection showed no blown fuses, Power would cut intermittently before total failure I recommend having the wiring between the ignition switch and starter solenoid checked carefully. The repair cost in my case was 175€ including parts and labor. Does your starter make any sound at all when turning the key?

Thanks for sharing those details about your Sharan's electrical issues. My Touran actually exhibited almost identical symptoms before the complete failure. The starter gradually became more inconsistent over about a week before stopping completely. I forgot to mention in my first response, but my starter was completely silent when turning the key, just like yours. The wiring harness connecting to the starter solenoid turned out to have significant wear where it flexed near the transmission housing. The battery terminals were also showing early signs of corrosion which could have contributed to the problem. The workshop ran a full diagnostic and found error code P0682 as well. They traced the circuit interruption through the entire ignition system path and found multiple weak points: Corroded battery terminal connections, Damaged wiring harness insulation, Worn ignition switch contacts Total repair ended up including: New wiring harness section (85€), Ignition switch replacement (65€), Battery terminal cleaning and protection, Labor (95€) After the repair, they recommended checking the starter solenoid and relay switch connections every 2 years as preventive maintenance, especially given our similar model years having this weakness.

Thanks for the input regarding your Touran experience. After hearing your complete repair story, I'm convinced I have a nearly identical power supply issue in my Sharan. No starter sound matches what you described, and the gradual failure pattern is the same. The voltage drop symptoms and P0682 error code alignment are particularly telling. I checked my battery terminals again and found slight corrosion starting to build up, which likely contributed to the failure just as in your case. Based on the comprehensive fix you had done, I'll request my mechanic to: Check the entire ignition circuit, Inspect the relay switch connections, Test the starter solenoid, Examine all wiring harness sections for wear, Clean and protect the battery terminals The total repair cost of 245€ in your case seems reasonable for the work involved. I'll schedule the repair this week and make sure they do a complete circuit check rather than just replacing individual components. Good suggestion about the 2-year preventive maintenance schedule for the starter and relay components. I'll add that to my service calendar to avoid future failures. Do you recall how long the complete repair took at the workshop?