How to fix heated mirrors...

[Kam]

I've just successfully fixed both heated mirrors with very simple steps. I tested them and man they are HOT. My original reading with multi-meter was
650-700 K-ohms (Before) and now its around 11-13 Ohms. I don't want to write something that no one cares about. So if few people are interested then I'll post the pictures.

Kam

[SQ Bimmer]

I don't have em, but people frequently ask about them and don't get much of a response. So I'm sure anything will be great for this section.

[al_r]

I'm interested and have the winter package; the glass on both of mine is fine, but no heat...

[1996 328ti]

If someone needs to replace their mirrors, BMW makes a convex left side mirror. I'd have to dig up the part numbers. They have them for E36 mirrors, M3 mirrors. It gives a wide view of the left side. It takes a little while getting used to but when you get into a US spec left mirror you really see what you have been missing.

[Jimmie Jazz]

I've just successfully fixed both heated mirrors with very simple steps. I tested them and man they are HOT. My original reading with multi-meter was
650-700 K-ohms (Before) and now its around 11-13 Ohms. I don't want to write something that no one cares about. So if few people are interested then I'll post the pictures.

Kam

I'd like to see your write-up and pics!

[lovesm3s]

i always wondered if i have heated mirrors i've tried touching them but they're not hot. however the passenger side clears up really fast compared to my driver side?? how do i find out if i have heated mirrors and can i get heated mirrors if it wasn't on my car in the first place?

[hc1001]

Kam: what was wrong with ur heated mirrors? i kno some euro spec e36's dont have heated mirrors. did u have heated mirrors b4?

most US e36 have heated mirrors except for some european spec ones... they only activate when its below a certain temperature. i thought by going with aftermarket m3 mirrors i would lose this feature. i swapped my regular 3 series mirror motors into the aftermarket m3 ones and last winter, they heated up the mirrors. u can see its working by feeling the mirror or seeing the snow melt off of the mirror glass. this only works when the ambient temp is lower than 43F or some other number, i think... all i kno it mines worked.

[1996 328ti]

US heated mirrors are always on.

[Kam]

I live in Ottawa Canada and here we have very cold winter with lots of freezing rain and snow. For a while I was under the impression that I don't have heated mirrors because they were colder than ice. I called couple of BMW dealers in the city and they told me the same: "$300+ for both and they often burn out in couple of months any way!" I decided to keep the $300 and clean the mirrors manually . Everything was fine until last week which we got hit by heavy freezing rain and lots of snow. My car (parked outside) was turned into an ice cube! I had to use hair dryer to defrost the mirrors for 20 Min. Still I wasn't pissed until my neighbor with his neon told me his car has heated mirrors and it's awesome! That was it, I needed the heated mirrors... Here are the steps...

I am not responsible for any damage to your mirrors.

1-Removing the mirror lens. (refer to Bentley manual and make sure car is in room temperature or above otherwise you are going to break some plastic parts)

2-Tools: These are the tools I used and you may not need all of them:
- 25 Watt Solder gun (Must)
- Rosin Core Solder wire (Must)
- Tweezers (Optional)
- Small flat head screwdriver (Must)
- Multi-meter (Must)
- 9 or 12V, 15W or higher DC power supply (Optional)
-Alligator clips (Optional)
*See picture Tools.jpg

3- Use the Alligator clips and connect the multi-meter to the lens power plugs. I found out the readings are very high (3.37 KOhms) which should be something close to 10-20 Ohms.
*See picture Pic-1.jpg

4- In order to access to the heating elements (similar to rear window defroster) I used the gaps under the housing clips.
*See picture Pic-2.jpg

5- Use the flat screw driver and shave off the resin very carefully (I did all 4 of them) you should be able to see the copper lines.
*See picture Pic-3.jpg

6- Use tweezers or flat screwdriver to short the copper lines. The multi-meter should read 10-20 Ohms if so (Bingo) go to the next step otherwise (F***) move to the next spot.

7- Make sure your Solder gun is very hot and keep it over the clips above the copper contacts. Be careful don’t melt anything. Attach the rosin core solder wire to the tip of the solder gun. The rosin solder wire instantly melts. Continue feeding the solder gun tip with rosin core solder wire. After a few seconds the melted solder will drop exactly over the copper contacts with out melting or damaging any thing. Thanks to gravity
*See picture Pic-4.jpg

8- Now readings on the multi-meter should be much lower like 11.5 Ohms in my case. Done, enjoy your heated mirror...
*See picture Pic-5.jpg

Before installing the mirror lens use the screwdriver and shake the solder and make sure it is secured completely. I used the DC power supply and tested the mirror lens and it instantly warmed up. Don’t keep it to long because it may burn your DC adaptor. I didn't bother to cover the shaved spots with anything yet but you can find a heat resistance glew and cover the shaved spots.

I did both mirrors and end up exactly the same spot (pic-5)! Is it just a coincidence or a manufacturing flaw? Good luck

My next project? use a timer switch or plug the heated mirrors to climate control defroster

[Kam]

Here is the pic-5

[RayMan]

Kam, what do you mean by "hot"? I have one dead mirror and one working. The working one is about 28 degrees Celcius (about 82 Fahrenheit). Is your's hotter than that after your fix?

[Kam]

After a few minutes they get very hot, way more than 28c for sure. last night here was -22c and when I was removing the snow from the car the mirrors got covered by some flicks and after 2 minutes or so the snow melted and mirrors were completly dryed. I would think they are about 50c-75c hot! After all outside temp. was about -22c!

[RayMan]

After a few minutes they get very hot, way more than 28c for sure. last night here was -22c and when I was removing the snow from the car the mirrors got covered by some flicks and after 2 minutes or so the snow melted and mirrors were completly dryed. I would think they are about 50c-75c hot! After all outside temp. was about -22c!

-22 huh?! I was in Ottawa a week before Christmas and it was around -17 at the time. I'm so glad I missed -43C two days after I left. Is the Canal thick enough for foot traffic yet?

Anyways, 50 to 75C sounds a bit too hot. (That's 122 to 167 Fahrenheit!) My wild guess is that these mirrors were not designed to get that hot. I wonder if this puts an extra strain on your electrical system. Keep us updated with any problems.

Thanks!

[Kam]

Today here is +8c and rain!

According to Bentley there is a thermal switch that control the voltage and therefore the heat. I'm going to check them today in warmer temp. to find out how hot they get when outside if warm.

You are absolutely right about damaging the lens and housing by over heating. If this is the case (I hope not) I am working on a method to plug the mirror heating elements to rear window defroster so they can stay off when you don't need them!

Kam

[Kam]

As far as Canal goes it opened last week and I think they closed it today due to +8c.

[RayMan]

+8!? sounds like a heat wave...lol. I think a switch is a great idea. But rather than wiring them in to your rear window defroster, why don't you just wire them to a separate switch? Use something like this: http://www.radioshack.ca/estore/Prod...roduct=2758096
in one of your empty panels above the shifter. I think a separate switch is probably more practical since the rear window defogger is usually working on the glass inside the car whereas the mirrors are outside so they face different conditions. Not to mention, the separate switch is probably simpler to install.

[Kam]

A separate switch is cheaper for sure. I have an extra relay (T512 I think) and conecting it to defroster or a switch basiclly are the same. I would like a push button rather than a switch so it won't stay on. A push button and a timer relay (adjustable)
can let anyone to adjust the total time for the mirror. Same as rear window defroster. I have to think about it little more... Thanks for the feedback

[M3Armand]

3- Use the Alligator clips and connect the multi-meter to the lens power plugs. I found out the readings are very high (3.37 KOhms) which should be something close to 10-20 Ohms.

8- Now readings on the multi-meter should be much lower like 11.5 Ohms in my case. Done, enjoy your heated mirror...
*See picture Pic-5.jpg

Kam, in reading your meter, it looks like it's in the KOhms range. Thus, isn't that actually reading 11500 Ohms vs. 11.5 Ohms as you stated? I'm curious since mine (1999 M3 with 45k miles) reads about 1200 Ohms, but it's not working. I checked the wires leading up to the mirror and I do read a little over 12 volts going into the mirror. So I hope I'm reading the meters wrong since I have no clue as to why my mirrors won't heat up anymore.

Also, where did you get the info that the reading should be 10-20 Ohms?

Thanks!
Armand

[Kam]

Kam, in reading your meter, it looks like it's in the KOhms range. Thus, isn't that actually reading 11500 Ohms vs. 11.5 Ohms as you stated? I'm curious since mine (1999 M3 with 45k miles) reads about 1200 Ohms, but it's not working. I checked the wires leading up to the mirror and I do read a little over 12 volts going into the mirror. So I hope I'm reading the meters wrong since I have no clue as to why my mirrors won't heat up anymore.

Also, where did you get the info that the reading should be 10-20 Ohms?

Thanks!
Armand

Armand, If you look at the LCD it shows 11.5 and small icon on the right shows Ohm logo. If it were 11500 Omhs (11.5 KOhms) then the LCD would show 11.5 and the lower right logo displays KOhm (See pic_2 it shows the Kohms on the corner). As far as were I've got the numbers well you can call it a hunch? Just kiddin', I don’t want to get in to physics lessons but in simple words in order to create heat from electricity you should have a very low resistance along the path of a wire, same as house hold electric heaters. The resistance for the mirrors shouldn't be lower than 10 Ohms because it may cause melting the plastic housing and it shouldn't be more then 20-25 because it would not be hot enough! Since I only shorted two lines I have to be 20% off in numbers. However I didn't measured a brand new mirror yet to be exact. In my 20+ years of experience in electronics I've never seen two identical resistors to have the same value. There is a tolerance of 10-15% of accuracy for average electronics components.

Good Luck

[old skool]

very cool....The separate button idea is cool but I wouldn't care personally about the time relay...however it would be good if the button had an led to indicate if it was on or not.

[rdtx2005]

bump up this old thread.. since winter is coming.

[Kam]

Thanks for the bump. I forgot about this thread

[CirrusSR22]

Alright guys, I need some help with the theory of this whole thing. I've had my car for two full winters, and have never noticed the mirrors heating or melting ice. I assume they're broken, so I decided to try and fix them.

I pulled the mirrors off and the voltage from the supply was 11.9 volts, engine off, and 13.8 (or so) with the engine running. Good, it's getting power. I then tested the continuity of the heating element. I assumed it's a closed loop, but nothing. I pulled the mirror from it's backing and traced the fine flat wires only to find the wires just "dead end". Each terminal is not connected to the other one. How do this system work then?

I did test the resistance between each terminal and got 66.5k Ohms. But if you check the resitance between each half of the wiring (terminal to "dead end") I get 5.5 Ohms each.

[Kam]

Good job on opening it. In order to get the heating elements to work, it must be a close loop. Look for two spot that will give you around 10-15 ohms. Use a pro DC adaptor (3+ Amp) and connect them. You should feel the heat. otherwise pick two other spots.

[CirrusSR22]

I opened it up by running tap water over the mirror then slowly increasing the temperature. The hot water in my place is REALLY hot (175F), so that helped. I then pulled the mirror from the backing very slowly by hand. The adhesive is very tacky so it slowly releases itself.

What I don't understand is why the wiring is open loop by design? I can't even fathom how that would work.