VW Caddy Voltage Drop Draining Power and Systems

Had nearly identical electrical problems with my 2006 VW Golf GTI. The battery health seemed fine initially, but the symptoms matched yours exactly, dimming lights, hard starts, and unusual electrical failures. The alternator issue became apparent when voltage readings dropped below 13V while running. After a thorough diagnosis, the problem was a failing voltage regulator inside the alternator, causing inconsistent charging. The battery terminal connections were also corroded, creating additional resistance in the charging circuit. The fix required: Complete alternator replacement, New battery terminals, Battery load test to verify health, Full electrical system diagnostic This was a serious electrical problem that could have left me stranded if not addressed. The old alternator was actually damaging the battery due to improper charging cycles. The repair resolved all symptoms, strong starts, stable lighting, and proper system operation. Key warning signs were the flickering lights and system failures, which clearly pointed to charging system problems rather than just a weak battery. Getting it fixed early prevented more extensive electrical damage.

Thanks for sharing that experience. Had the exact same symptoms with my Caddy last winter, weak starts and flickering dash lights. Your alternator diagnosis sounds spot on. The voltage readings I got were also consistently below 13V under load, which definitely pointed to charging system troubles. The shop found similar issues, bad voltage regulator and corroded battery terminals creating extra resistance. Wondering what total repair cost you ended up paying? Also curious if youve had any other electrical gremlins pop up since the fix? My Caddy has been running fine after the repairs, but always good to know what to watch out for.

After getting everything sorted at the mechanic, I can confirm the undervoltage detected was completely resolved. The total repair came to 290€, which covered replacing the heavily discharged battery that turned out to be defective despite its age. The electrical system has been rock solid since the fix, no more voltage drop issues or starting problems. The battery health is now excellent, maintaining proper voltage even under heavy loads. When they tested the charging system, all readings came back normal. For peace of mind, I keep a basic voltage meter in the glovebox to occasionally check readings, but havent seen any concerning numbers in the months since the repair. The investment was worth it to avoid potential electrical problems down the road that could have left me stranded. The voltage regulator and charging system are working exactly as they should now, no more flickering lights or system glitches. Seems like catching these electrical issues early prevented more extensive damage.

Thanks for the helpful info. Finally got my Caddy sorted last week after dealing with those electrical gremlins. Took it to a different shop this time, much better experience. The mechanic found the charging system was failing due to a bad voltage regulator and some corroded connections. Total bill came to 320€ for parts and labor. They replaced the alternator, cleaned up all the terminals, and ran a full system diagnostic. What a difference now, strong starts every time, bright steady lights, and all electrical systems working perfectly. The voltage readings are sitting right where they should be at 14.2V while running. Such a relief to have it running properly again without worrying about getting stranded somewhere. Definitely learned my lesson about addressing electrical problems early before they cause more damage. The new shop did great work explaining everything and showing me the failing components. Much better than my previous mechanic who just wanted to throw parts at it without proper diagnosis.