VW Crafter Signal Light Fault After Mechanic Visit

Had a similar electrical fault on my 2013 VW Transporter TDI. The signal lamp warning kept showing up despite replacing the bulbs. The issue turned out to be more complex than a broken lens or basic lamp replacement. The root cause was corroded connections in the main wiring harness leading to the rear lights. The flasher relay was functioning correctly, but poor connectivity caused intermittent signals to the control unit. The repair required cleaning all connection points and replacing several damaged wire terminals. When dealing with persistent lighting system warnings, its worth checking: All ground connections for corrosion, Wiring harness for damage where it flexes near doors, Connection quality at the fuse box, Integrity of the main plug connections This kind of electrical issue often appears minor but can indicate more serious wiring problems. In my case, leaving it unaddressed could have led to complete lighting system failure. A proper diagnosis using electrical testing equipment is essential rather than just replacing parts. The lighting system on these vans shares similar architecture, so the symptoms match what you describe. Would strongly suggest having the wiring harness and connections properly inspected rather than focusing only on bulbs or the flasher relay.

Thanks for sharing that detailed explanation about the wiring harness issues. Your experience with the electrical fault actually sounds really similar to mine. Getting to those corroded connections definitely fixed most problems, but I still had an occasional turn indicator warning for a few weeks after. Before finding the actual issue, I wasted money replacing both the flasher relay and a broken lens that I thought might be triggering the system. Would you mind sharing what the wiring harness repair ended up costing you? Also curious if youve had any other lighting system problems since getting it fixed?

Thanks for the follow-up. After having the turn signal lamp issue properly diagnosed, the repair was straightforward and cost 95€ to fix the faulty cable connections. The warning lights completely stopped after addressing the actual electrical fault in the wiring. Unlike your experience with unnecessary parts replacement, going straight for the wiring inspection saved money in the long run. The mechanic found the issue was simply a loose plug connection that was causing intermittent signal lamp failures. Since getting the proper repair done six months ago, the lighting system has worked flawlessly. No more dashboard warnings or bulb replacement needed. The key was correctly identifying the root cause rather than swapping parts hoping to fix the electrical fault. For others reading this thread, if you get persistent turn signal warnings, have the wiring and connections checked first before replacing bulbs or relay components. A proper electrical diagnosis can prevent spending money on unnecessary repairs.

I finally decided to take it back to a different mechanic who actually knew what they were doing. The job cost me 180€ total, mostly labor for tracing and fixing all the corroded wiring. They found several bad connections that the previous shop completely missed. After the repair, all my automotive lighting issues cleared up completely. No more signal lamp warnings on the dashboard. Turns out I really didnt need that new flasher relay or lens replacement, just proper electrical diagnosis and repair of the wiring harness. The mechanic showed me the corroded connections they found and explained how water had gotten into the main wiring bundle. The electrical fault was causing intermittent issues that generic parts replacement wouldnt have fixed. Lesson learned about finding a shop that actually investigates the root cause instead of just swapping components. For anyone else with similar issues, get the wiring checked first. Three months later and everything is still working perfectly. Would have saved money going there first instead of trying the quick fixes that didnt work.