What is the reason for the Volkswagen mirror heating not responding?
3 Answers
Volkswagen mirror heating not responding because the heating requires some time, you can press the heating button and wait for a while to see if it works. Additionally, if there is no effect for a long time after pressing the switch, you can check whether the fuse is normal. More information about the mirror heating function is as follows: 1. Mirror heating function: When driving in rain, snow, fog, or other weather conditions, the mirror can be heated by the heating wires embedded behind the mirror to ensure the surface of the mirror remains clear. The car mirror heating is generally more suitable for rainy or snowy days. When the mirror is heated, the heater behind the mirror quickly heats the surface, gradually removing rain or fog from the mirror, saving the driver the trouble of frequently wiping the mirror manually, thereby reducing driving risks. 2. Working principle: An electric heating element (heating film) is installed inside the mirror of both side mirrors. In rainy or snowy weather, when the owner turns on the mirror heating function, the heating element will quickly heat up to a fixed temperature within a few minutes, usually between 35-60 degrees Celsius, thereby heating the mirror and removing fog and frost.
My previous Volkswagen also had this issue - the rearview mirror heating button didn't respond, which was particularly annoying especially during rainy days when visibility was poor. The most common cause is a blown fuse. Go to the engine compartment fuse box, check the diagram on the cover to locate the fuse labeled 'Rearview Mirror Heating' or 'Heating Device', then try replacing it with one of the same specification. If the fuse is fine, it's likely that the heating wire inside the mirror glass is broken - this is hard to see with naked eyes and requires measuring resistance with a multimeter. Without tools, replacing the entire mirror glass is the easiest solution. Also don't overlook poor switch contact, especially in older cars where the switch contacts may have oxidized from prolonged use - try pressing it repeatedly to see if it works intermittently. Additionally, check the wiring harness connectors inside the door panel - remove the trim to inspect for loose connections or exposed wires causing short circuits, as wiring harness aging is quite common in Volkswagens. If all else fails, you'll need to check the heating control module, though this is less likely to be the issue.
Don't panic if the rearview mirror heating fails—it's usually a few hardware issues. I've taken mine apart several times, and the most common culprit is the heating resistor wire on the back of the glass. If it suddenly stops working on rainy days, it's likely due to aging. The fuse is located in the fuse box on the left side of the engine bay, usually a small yellow 5A or 10A piece—pull it out and check if the middle is blown. If the switch button doesn't make a clicking sound when pressed, it's poor contact, and you'll need to spray some contact cleaner. Another possibility is the background program controlling the heating acting up—try turning off the engine, locking the car, and waiting ten minutes before restarting. Sometimes the electronic system just freezes and can recover on its own. If you don't want to bother, spend a little money at the repair shop to have them plug in a computer and read the fault codes. For wiring issues, they can quickly locate any breaks with a multimeter.
