Heated Mirror Harness

[Japandrew73]

Can anybody show me a diagram or pictures of what wires go where for a heated mirror setup? I know that I must have the mirror glass with the two prongs on it, but then what?

Are they hot all the time or only when the rear defroster switch is activated?

[atomic]

Not sure what is needed for your request... I do believe they are activated by the use of the rear defroster however

But there is (and it might be a part of the heated mirror harness) a heated door lock too, that is activated by lifting up on the door handle to thaw the driver side lock so you can unlock the car (but this could be wired completely different as well)...

[Japandrew73]

Well, I'm about 90% sure the heated locks are separate. But My request is what exactly do I have to do to retrofit a heated mirror? I need to get the glass with the two prongs on the back, and then what?

[bmwpower]

Just checked the electrical diagrams...no heated mirror info...unless I'm blind.

[Japandrew73]

well I don't have any electrical diagrams. that's why i posted this thread. I just need an explanation of what I need to wire, once I have the glass with the two prongs.

[atomic]

Here is a link to the wiring diagrams on the different year model e30's. Go have a look around to see if you can find anything.

I did search around on realoem.com and can not find anything to do with the wiring harness for the heated mirrors. I can find the heated lenses and the heated door locks (which appears to be completely seperate from the mirrors)....

http://www.kneb.net/bmw/E30/

:up:

[Japandrew73]

Thanks! This would help if I could read these haha. Is there a simpler way you could describe hot to wire them in?

Edit: I THINK I have figured it out.

The two black wires that go down in this pic attach to the 2 prongs on the mirrors.

The other ends of the two black wires go into the same connector that the power mirror wires are into. So they basically tap into them.

One taps into the blueish green wire (power) and the other taps into the brown wire (ground).

Now my question is, when wiring it this way, how is it activated? is it always hot, or is it hot on ignition, or is it hot with the rear defroster switch on?

[bmwpower]

I *think* it's hot on ignition. The reason I say this...If you have condensation on your mirrors in the morning, after you drive around a little, it will be gone. I believe I had one side that wasn't working since it would never "dry up"...just guessing.

Always hot would not make sense...totally drain battery.

[lylefk]

Put a test light or multimeter on the bluish green wire, turn the ignition on, see if it shows 12 volts. If not, hit the rear defrost button. If it still doesn't, I dunno...try everything. Shouldn't be too tough.

[atomic]

OK I just looked into my owners manual from my 1991 325i and it says for "the electric mirror heater : the outside mirrors are electrically heated automatically"

So you might be on to something from above...

[lylefk]

You could really wire it however you want...ignition makes the most sense.

[Japandrew73]

hmmm i guess hot on ignition makes sense. But how fast do you think it heats up?

I'll do that test Lylefk thanks for the idea. I guess it makes sense that they are hot on ignition because the power mirrors only work when your car is fully on or into the 2nd turn of the key so that your wasting as much battery as possible. So if your tapping into the blue wire your using the same principles as the power mirror switch.

I'm just thinking that if the heated door locks are activated by pulling the door handle up, how long would you have to hold it up in order to heat the lock you know? Unless it heats super fast then you would have to hold up the door handle for a while, like a couple of minutes.


Thanks for all the help you guys, the install seems pretty simple.

Although all my power mirror wires aren't open like in the pic, they are in a plug housing so I guess i'll just tap into it further down in the wire.

[Japandrew73]

OK I just looked into my owners manual from my 1991 325i and it says for "the electric mirror heater : the outside mirrors are electrically heated automatically"

So you might be on to something from above...

wait... what does that mean? automatically like hot all the time or hot on igniton?

[atomic]

wait... what does that mean? automatically like hot all the time or hot on igniton?

I would assume hot on ignition since it appears to pull its power/ground from the power mirror harness itself from what you pictured above...

[Japandrew73]

Ok cool, I understand fully now. Thanks for all your help guys. Now I just need to get the Heated Mirror with the prongs and the wiring will be simple and cheap! :D