VW Transporter No-Start: Terminal 15 Power Supply Fix

The symptoms match what I experienced with a 1998 VW Golf (2.0L gas). The ignition switch was failing to deliver proper voltage to terminal 15, causing intermittent starting issues. After checking the fuse box and finding no blown fuses, the diagnostic revealed a significant voltage drop at the ignition circuit. The root cause was a deteriorated relay switch that was causing poor contact. The aging wiring harness connectors near the steering column had also developed resistance, further compromising the power supply to the starter circuit. This was a serious electrical issue that required complete replacement of the relay switch assembly and reconditioning of the main ignition circuit connections. If left unaddressed, it could have led to complete electrical failure while driving. The repair involved: Testing voltage at multiple points in the ignition circuit, Replacing the main relay switch, Cleaning and securing all ground connections, Installing new terminal connectors, Recalibrating the immobilizer system Would recommend getting this checked soon, as these symptoms typically worsen over time and can leave you stranded.

Thanks for sharing your experience. I had nearly identical symptoms with my Transporter last winter. The starter solenoid was getting inconsistent power due to corroded battery terminals and a damaged section of the wiring harness near the firewall. The circuit break was causing the same error code you mentioned. After fixing those issues plus replacing a worn relay, the starting problems completely disappeared. Would be curious how much your repair ended up costing and if you have noticed any other electrical quirks since getting it fixed? My total came to around 450€ for parts and labor.

Just had my VW back from the mechanic yesterday, the Terminal 15 ignition positive issue has been fully resolved. The problem turned out to be less severe than yours, mainly involving a faulty cable connection near the starter solenoid. The repair was straightforward once they traced the exact point of interruption in the wiring harness. The total bill came to 95€, which included testing the entire ignition circuit and securing the loose connection. Much cheaper than your repair since no parts needed replacement, the existing relay switch and battery terminals were in good condition. Since the fix, the car starts perfectly every time with no error codes. The mechanic also checked the rest of the electrical system while it was in, and everything else tested normal. No other electrical quirks have appeared, which is a relief considering how these issues can cascade if left unchecked in the fuse box area. Your case sounds more complex with the corroded components. Smart move getting those battery terminals and damaged wiring replaced, prevention is always cheaper than dealing with a complete electrical failure.

Thanks to all who replied. Just got back from the mechanic and wanted to share how it went. The power supply to the starter solenoid was indeed the culprit. Found significant corrosion in the fuse box and a failing circuit break that was causing the voltage drops. Total repair came to 380€, covering: New starter solenoid, Fuse box cleaning and protection, Battery terminal replacement, Labor costs The mechanic discovered the original battery terminals were completely shot, way worse than initially thought. They also found and fixed some minor wiring issues while in there. Car starts perfectly now and all error codes are gone. Big relief to have this sorted before winter hits. Worth every cent compared to being stranded somewhere with a dead starter.