Dead RS4 Mirror Heaters Need Expert DIY Solutions

Had the same issue on my Audi S4 1997. The car electronics diagnostic showed a faulty connection between the mirror heating control module and the heater element itself. Winter driving became challenging when the mirrors kept freezing over. The mirror replacement was not necessary in my case. The main problem was a corroded wire harness connecting to the temperature control unit. The connections had deteriorated over time due to moisture getting into the door panel. The repair involved accessing the wiring through the door panel, cleaning the connector pins, and applying dielectric grease to prevent future corrosion. This is not a serious repair if caught early, but leaving it unfixed can lead to moisture damage in other electrical components. The heater element itself was functional, just not receiving proper power due to the bad connection. A proper diagnostic scan will reveal if your issue is similar, look for codes related to mirror circuit resistance or connection faults. The repair requires specific knowledge of car electronics, so finding a technician familiar with Audi electrical systems is important.

Thanks for your detailed response regarding the mirror heating issue. My situation sounds very similar, especially the corrosion problem affecting the heater element during cold weather. Having someone confirm a similar experience helps narrow down where to look. Could you share what the repair ended up costing? Also curious if youve had any other rearview mirror or electronics issues since getting it fixed? The car is currently at a specialist who seems confident about the diagnosis, but Id like to have a rough idea of the expected costs before proceeding.

Thanks for asking about the costs. Since fixing the faulty wiring connection in my rearview mirror heating system, everything has worked perfectly through two cold weather seasons. The repair cost me 95 Euro, which covered cleaning the corroded connections and replacing a damaged section of the temperature control wiring. The winter driving experience has been much better with properly functioning heated mirrors. The specialist was right about the diagnosis, it was indeed just a wiring issue rather than needing a complete mirror replacement. The repair took about an hour and the technician applied protective coating to prevent future corrosion. No other electrical problems have occurred since the fix. The mirror heating now activates promptly when temperatures drop, exactly as it should. Sounds like youre on the right track with your specialist, and the repair cost should be similar if its the same issue.

I appreciate all the helpful responses. After dealing with the electrical fault in my mirror heating system, I wanted to share my experience. I took the car to a specialist auto electrician who immediately identified the corroded wiring as the core issue, just as suggested here. The repair took about 90 minutes and cost 120 Euro, which included cleaning the connections, replacing a section of damaged wiring in the temperature control system, and applying protective coating. The technician showed me the corroded parts, and it was clear why the mirror heating had failed during winter driving. The fix has been perfect, all mirrors now heat up properly in cold weather. The specialist also checked the rest of the car electronics while it was in, confirming no other issues. Much better experience than my previous mechanic, and the cost was reasonable for the work done. The car now performs exactly as it should in winter conditions. Really glad I got this sorted before more serious electrical problems could develop. Thanks again for pointing me in the right direction with the diagnosis.