[DreierTouring]

Hi everyone,

Do all 3-pin side mirror housings support autodimming mirror glasses?

For context, my side mirrors are in various states of disrepair. They have autodim, power folding, memory and reverse dip. Finding complete, identically-equipped mirrors for a reasonable price has turned out to be shockingly difficult. Most of the used ones I could find for sale are 5-pin rather than 3-pin, and of the few 3-pin mirrors on the market, even fewer have autodimming mirror glasses (and go for $$$).

My new plan is to just source a used pair of non-dimming 3-pin mirrors, salvage the dimming mirror glasses I have in the broken housings on my car, and install them onto the donor housings.

Would this work, or would the donor mirrors have to be off a car with autodimming?

Thanks

[ptpending]

you can install non-auto-dim mirror assemblies, but it is better to code out auto-tim function from car

[Serf27]

Auto dimming is a great feature that is taken for granted until don’t have them!

[Andystobbs]

You would also need to swap over the electronics from inside the original mirrors.

[DreierTouring]

Originally Posted by Serf27

Auto dimming is a great feature that is taken for granted until don’t have them!

Absolutely, especially living in a place infested with obnoxiously large pickup trucks.

Anyway, on my end, after hours and hours of sleuthing various parts websites, I got lucky and found exactly what I wanted. I snagged a nice pair of dimming, power-folding mirrors with seat memory that had been freshly listed on ebay, shipped to me from Lithuania for a total cost that is less than what my local BMW scrapper charges off the rack.

(Note: if anyone reading this wants to go the same route, make sure you buy a pair that is for your driving side - LHD or RHD.)

A nice bonus is that they're Euro-spec, so they have wide-angle lenses on both sides. I will post an update once I install them after they arrive, and verify whether they work as expected.

[DreierTouring]

Originally Posted by Andystobbs

You would also need to swap over the electronics from inside the original mirrors.

Here is some information I found on mirror packages on an older thread (credit to Ao1 and bishbosh):

[430]
Exterior and interior mirrors - folding, automatically dimming
Electrically foldable mirrors
Memorised adjustment controlling door mirror position
Door mirrors ; light sensitive, door mirrors ; light sensitive with automatic tilt feature when reversing
Heated washers
Includes:
[431] Rear-view mirror - automatically dimming
Excludes:
[313] Exterior mirrors, folding

3-pin mirrors are controlled via LIN bus, while 5-pin mirrors are directly controlled from the footwell module. Autodim and seat memory settings are only possible via LIN bus control, so any car with option 430 will have the 3-pin mirror, and any car with option 313 or the base manual folding mirrors will be 5-pin.

Confusingly, most of the 3-pin mirrors I found came off cars that only have option 431 rather than the full option 430, which is much rarer than I expected, especially in continental Europe. So they would have the dimming interior rear-view mirror, but no dimming side mirrors nor memory seat settings.

So if I were to take a 3-pin mirror from a car with option 431 only, plug it into my car which is equipped with option 430, wouldn't that mirror be able to receive the commands from the footwell module of my car, including those for memory settings and autodim?

And if the above were true, if I were to also install the dimmable lenses from my option 430-equipped car onto them, wouldn't those donor mirrors also be able to operate the dim function on those lenses?

If the answer to both of the above is true, then all 3-pin mirrors should have the same electronics, regardless of the spec of the car they are mounted to. The only difference would whether a dimmable lens is installed onto them. This is what I am trying to determine the answer to.

[ptpending]

there are fold-in mirror assemblies with memory but without autodim
they have different mirror electronics because the outside autodim mirrors have different connector (4-pin) while heated only mirror have 2 separate pins on mirror back

[DreierTouring]

That’s exactly what I was looking to determine. Thanks!

[Matt_E90]

The auto dim glass has a bronze'ish' tint? and the non dim is blue right?

[DreierTouring]

Originally Posted by Matt_E90

The auto dim glass has a bronze'ish' tint? and the non dim is blue right?

There is a very faint bronze tint for the autodimming mirrors. A deep bronze tint is oxidation. Tread carefully if you are shopping.

Normal:



Oxidized:



All blue-tinted mirrors are non-dimming. Though non-dimming mirrors can also be clear.

[Serf27]

Look at the photos above. Lci dimming mirror has a tint and the 1/4” border of the glass is clear.
Pre lci dimming mirrors have a black plastic border, while the non dimming has no border.

[ptpending]

Originally Posted by Serf27

Look at the photos above. Lci dimming mirror has a tint and the 1/4” border of the glass is clear.
Pre lci dimming mirrors have a black plastic border, while the non dimming has no border.

there were also transition LCI auto-dim mirrors which had plastic border too

[Matt_E90]

Really helpful those replies guys thankyou 👍