Amarok Window Defroster Issues: Fix Urgent for Winter

I dealt with a very similar heating issue on my 2012 VW Transporter T5 last winter. Having some experience with car electrical systems, I first suspected a fuse problem, but it turned out to be more serious. The symptoms were identical, inactive rear defroster and weak front heating performance. The workshop diagnosed a severely discharged battery that was no longer holding proper charge, which caused multiple electrical systems to malfunction, including the window demister circuits. The complete fix included: Battery replacement, Electrical system diagnostic, Testing of all heating coil circuits, System reset and calibration Total cost was 290€ and the defroster repair resolved all heating issues completely. The workshop explained that a weak battery can cause these symptoms because the heating systems require significant power to operate properly. Before suggesting specific solutions for your Amarok, could you share: Battery age and last replacement date, Whether the heating issues started gradually or suddenly, If you notice any other electrical issues like dim lights or slow starter, Current battery voltage reading if you have access to a multimeter This information would help determine if your problem might have the same root cause.

Thanks for sharing the repair details. My Amarok just had its service at 99692km where they checked all fluids and filters, but the heating coil problems started shortly after. The auto defrost did work fine before that. The window heater issues appeared suddenly, one morning the rear heating just stopped completely and the front window demister barely produces any warm air. No problems with lights or starting though. Just checked the battery voltage which reads 12.4V at idle. Would definitely be relieved if the fix was as straightforward as yours at 290€. I will have the workshop check the electrical system and heating circuits first before replacing any major components.

Thanks for those details about your Amarok. The 12.4V reading is actually borderline, while not critically low, it might not provide enough power for high-draw systems like the thermal window heating elements. Since your issues started right after the service, its worth checking if any connections were accidentally disturbed during maintenance. The auto defrost and window demister systems share some electrical pathways, so a loose connection could affect both. In my T5 case, even with normal starting power, the battery wasnt strong enough to maintain proper voltage under load when the heating systems activated. The workshop found that replacing just the battery didnt fully solve it, they needed to clean all ground connections and verify the alternator output. A few specific things to have checked: Alternator output under load, Heating relay function, Ground connection integrity, Thermal fuse condition The good news is that since your battery voltage isnt severely low and the timing coincides with recent service, this might be simpler than my repair. Have them start with checking those service-accessible connections before replacing components.

The symptoms you describe match my experience. After getting those voltage readings and knowing the timing after the service, I feel more confident about the potential fix. Really appreciate the detailed response about the alternator and ground connections, those werent on my radar. I will have the workshop focus first on inspecting all the connections that could have been affected during the service, especially around the window heater components. Good point about checking the alternator output under load before jumping to replace the heating coil or other expensive parts. Will book the car in next week and ask them to start with: Full electrical diagnostic, Check all ground points, Test heating relay and thermal fuse, Verify alternator performance Hoping the defroster repair ends up being a simple connection issue rather than needing major component replacement. Will share the outcome once I get it sorted. Thanks for helping narrow down where to start looking for the problem.