Earlier this week when we had our first bit of snow, I noticed that the side mirrors were not clearing up. I had thought that in order to activate the heated side mirrors, you set the adjuster to the center and hit the defrost button on the dash. Well, not so. What do I know? It's my first mk4. The rabbit had a fourth setting for the heated mirrors, so the operation was obvious. A little googling told me that people burn out the mirrors often for this reason. Bummer.
I loved the heated mirrors on the rabbit. Not having to scrape ice and readjust mirrors is a plus in my book Their use seemed to keep the mirrors nearly spotless of any dirt for some reason as well.
Anyhow, I looked up the prices of new heated mirrors. Dang it.. $100ish for the pair. Time for a little DIY! Another google search brought me to a clubTDI forum thread shoeing a successful replacement of the heating pad on the back of the plate with a length of resistance wire. I can do that!
I found 50 feet of 26 gauge resistance wire for $10 shipped, but I wanted to do the DIY this weekend because of the extra long Christmas weekend. Thursday I found myself at Grand River Hobby, buying two four foot lengths of foam cutting wire.

I doubled up the wire and used the hand drill to wind them up together to make about a foot and a half of twisted wire.
A little use of the multimeter and some online calculators showed me that I would be pulling less than a two amp draw per mirror. I hooked up the battery charger and put voltage and wire got toasty hot in ten seconds, too hot to touch, but not so hot as to melt the plastic backing after being on for over a minute.

The plastic mirror backing took a little careful work to pull off, and then the heat pad itself. Quite sticky glue used. I went to Canadian tire and got some small wire ends and added them to the resistance wire. The connectors on the car side were small and a little corroded, so I snipped them off and replaced those as well.
As you can see, I used some silicone to glue down the wire and plastic back plate. Also, sone epoxy was used to paste the wire connectors down into place since I didn't want the resistance wire to snap from vibration after time.
The mirrors snapped back into the housings easily again and I started the car. I turned the adjustment knob to the center and put away my tools. I came back after about one minute after turning the heat on and felt them. Nice and warm! A little window cleaner to take the fingerprints off and I was done. A total of about three hours of leisurely work.


Mercedes-Benz. The Cadillac of automobiles.