VW Amarok Charging System Failure, DIY Diagnosis Help

Had a similar alternator issue with my 2010 VW Transporter diesel. After experiencing those exact symptoms, dim lights, charging system warnings, and unreliable starts, I can relate to your situation. The first sign was the battery warning light, followed by electrical components acting strangely. The car eventually refused to start properly, leaving me stranded one morning. The charging system was clearly failing. After taking it to a workshop specializing in car electronics, they diagnosed a completely failed alternator. The repair included a new alternator unit, belt inspection, and testing of the entire charging system. Total cost came to 960€, which included parts and labor. The symptoms you describe match my experience exactly. However, to provide more specific guidance, could you share: Current mileage on your Amarok, Whether you notice the issues more during cold starts, If the battery has been replaced recently, Whether you hear any unusual noises from the engine bay These details would help determine if your situation matches what I encountered with my VW. A failing alternator is a common issue in these engines, but its best to confirm before spending money on repairs.

Thanks for your experience. My Amarok has 30993km and had its last service 3 months ago. The cold start issue is definitely there, gets worse each morning. No strange noises from the engine bay yet, but the battery is original from 2012. Your case sounds very similar, the way the electrical problems gradually got worse matches exactly what I am seeing. The battery warning light started flashing yesterday and the starter motor seems weaker with each attempt. Based on your repair cost, I should probably budget around 1000€ for the alternator replacement. Did you experience any engine misfire symptoms before getting it fixed?

Thanks for the additional details. Yes, before my alternator completely failed, I did notice occasional engine misfires, especially at idle. The voltage drop from the failing alternator can definitely affect fuel injection timing and ignition systems. Given your mileage and battery age, I would strongly recommend having both the alternator and battery replaced together. When my alternator failed at around 35000km, the original battery was also at the end of its life. The constant voltage fluctuations from a failing charging system can damage a battery permanently. The serpentine belt should also be inspected during the repair. In my case, they found some wear on the belt which could have contributed to the alternator issue. The total job ended up including: New alternator unit: 680€, Battery replacement: 180€, Belt inspection and tensioner check: 100€ The symptoms cleared up immediately after the repair. No more warning lights, strong starts even in cold weather, and proper voltage output restored. The engine ran much smoother too once the charging system was working correctly. Quick tip: If possible, limit short trips until you can get it repaired, as these put extra strain on an already weak charging system.

Thanks for the extra information about the belt and battery replacement. Those numbers help a lot with my planning. Making an appointment with the shop tomorrow since I dont want to risk getting stranded. The engine misfire symptoms you mentioned make sense, I noticed some roughness at idle yesterday that I didnt connect to the alternator issue at first. The original battery from 2012 definitely needs replacing anyway, so doing both jobs together is probably the smart move. Will have them check the belt too since its likely just as old. The complete 960€ repair solved all your issues, which makes me more confident about getting this fixed properly. Especially good to know about avoiding short trips. I will try to only use the car for longer drives until it gets into the workshop. With the voltage drop getting worse and the starter motor struggling more each day, I dont want to push my luck too far.