VW Transporter Power Supply Issues Causing Slow Starts

Had a very similar issue with my 2006 VW Caddy last winter. As someone with some basic car maintenance experience, I first tried the usual checks but ended up needing professional help. The symptoms were identical, slow cranking and multiple start attempts needed. After my own voltage drop tests showed inconsistent readings, I took it to a workshop. They diagnosed a combination of issues in the charging system: 1. Battery was heavily discharged and showing signs of internal damage 2. A partial short circuit was draining power even when parked 3. Corroded connections at the main fuse box were causing additional resistance The mechanic performed a complete charging system diagnosis, including testing the alternator output and checking all ground connections. The fix involved: Replacing the battery, Cleaning all terminal connections, Replacing a damaged wire section near the ignition switch Total cost was 290€ and it has worked flawlessly since then. To better assist with your case, could you share: Have you noticed any electrical issues besides starting? Does your battery warning light come on while driving? When was your last battery replacement? Have you measured the voltage across battery terminals while cranking? This would help determine if youre facing similar underlying issues.

Thanks for sharing that insight. Just had my service done at 65046km, and Im seeing almost identical symptoms to what you described. After checking your suggestions, I noticed my battery voltage drops significantly during cranking, similar to what you experienced. The voltage drop test showed irregular readings across different connection points in the wiring harness. I checked the fuse box connections as you mentioned, and there is visible corrosion buildup, which likely explains part of the resistance problem. The ignition switch area also feels a bit loose when turning the key. Those specific fixes you listed, especially the charging system inspection and cleaning the terminals, sound exactly like what I need. Its giving me a much clearer direction before I visit the workshop. Would you mind sharing how long the complete repair process took? Im trying to plan my schedule around the potential work needed.

Thanks for the update. Those symptoms definitely mirror what I experienced with my Caddy. The complete repair took about 4-5 hours at the workshop, mainly because they had to trace the entire power supply path to identify all weak points in the charging system. The loose ignition switch you mentioned is particularly concerning, in my case, this turned out to be a major contributor to the electrical fault. The mechanic found that the loose connection was creating intermittent contact, causing additional strain on the starter motor. Based on what youre describing with the voltage drops and corrosion, Id strongly suggest having them check: The entire length of the main power cable for hidden damage, All ground straps, including the often-overlooked ones under the battery tray, The starter motor solenoid connections The short circuit in my case was actually caused by worn insulation on a wire bundle near the steering column, something that wasnt immediately visible during basic checks. For reference, my repair included about 2 hours of diagnostic time to properly trace all the electrical issues, then another 2-3 hours for the actual repairs and final testing of the charging system. Given your mileage and symptoms, this sounds like a very similar scenario to what I dealt with. Getting it addressed soon will prevent potential damage to other electrical components.

Thanks for the detailed follow up about the repair timeline. Your experience really helps put things in perspective, especially about the hidden wiring issues. My next step is definitely booking a full diagnostic session. The voltage drop patterns and corroded fuse box match exactly what you found. After checking the starter motor connections more carefully, I also noticed some play in the mounting bolts that could be adding to the problem. Been going through the maintenance records and realized the power supply cables havent been inspected since I got the van. Given the symptoms and age, a complete charging system inspection makes total sense now. Will schedule a full day for the repairs to be safe. The 4-5 hour timeline you mentioned helps a lot with planning. Really appreciate the specific details about checking the wire bundle near the steering column too, will definitely have them look at that area. Planning to book it in next week and will make sure they do a thorough check of all the points you mentioned, especially those ground straps under the battery tray. Better to fix everything properly now than risk more electrical issues down the line.