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27 Posts
Discussion Starter · #1 ·
MKIV Auto-dimming Side Mirrors

Although the Golf came with an autodimming interior rear view
mirrors, afaik there were never similar door mirrors. With a little
investigation, a few months ago I realised the wiring to power
auto-dimming outside mirrors is already provided at the interior

If you look closely at the wiring at the interior mirror you can see the following:

Only wires 1-3 continue through from 4B0 971 834 into the connector (T6a / 4B0 971 833) for the loom that goes into the roof.

1. White - Fuse 5 7.5 Amp - blue black wire in roof harness)

2. Black - Earth 2 in dash panel wiring - brown wire in roof harness)

3. Light Blue - Reverse signal in plenum chamber

4. Yellow

5. Brown

6. Empty

So then looking at the wiring diagram from an Audi A6 you can see that wires 4 and 5 of their mirrors head off to the door mirrors.

For comparison, you can look at the MkIV wiring diagram here

Parts Required:

A car with the auto-dimming interior rear view mirror

Audi Auto-dimming mirror glass, as fitted to Audi A3/A4/A6/A8
around 1998-2003. There are loads of variations, but the first thing is
to pick what size glass you want.

125mm x 100mm

The 125mm x 100m size fits perfectly into a Lupo size stubby. The
problem is this size is only available for the right hand (RHD drivers)
side. There's no 125mm x 100m glass for the left hand side. I used this
size myself; it hasn't bothered me that the passenger side doesn't dim
- it's out of my eyeline.

4B1 857 536 L

150mm x 100mm

This is the size used for R32 stubbies and would be my first choice
size. Sadly there's no equivalent sized Audi auto-dimming glass.

175mm x 100m

The standard MkIV size. At the moment I don't have access to a MkIV
that I can snap the glass off, but by offering it up I reckon the Audi
glass would swap straight in.

There are about 10 variations of wide angle / flat / warning /
arabic / etc glass, so check on vagcat before buying. The
distinguishing features of auto-dimming glass are the black border on
the front and the extra socket and circuitry on the back.

4B0 857 536 A

4B1 857 535


About 2 meters for each side mirror.

2 x Spade connectors for each Mirror

For the heating element of the glass. You can get these in Halford's.

1 x 443 906 231 for each mirror

The connector for the auto-dimming wires at the back of the mirror glass.

Crimp Tool

You need to crimp wires at connector 4B0 971 833 (T6a at interior
mirror) and 443 906 231 (On back of mirror glass). The crimps should
come in the connectors. If you can't crimp the wires you need to buy
the repair wires 000 979 105 and 000 979 003 A (both bags of 5 short

Wiring Diagram:

Altered from BazMcC's diagram:


1. Removing the casing around the mirror base. Open up the
connector 4B0 971 833 (T6a). The unused crimps are already there in the
connector. Crimp wires on to point 4 and 5. To install mirrors on both
sides, split the wires in two to have 2 wires running to each side

2. Remove the sunvisors and wiring conduits and feed the new wires
up into the roof, down the A-pillars, into the door and up into the
mirror housings. You'll need to take the mirror housings apart.

3. The Audi mirror glass just snaps into place exactly the same as
the original glass (At least for the 125mm x 100mm glass, once I get my
hands on a MkIV with 175mm x 100mm mirrors I'll check them out).

4. Crimp the wires and place them in connector 443 906 231. Plug
the connector into the socket on the back of the mirror glass shown
Wire 4 from the interior mirror connects to the lilac wire on the Audi door mirror glass

Wire 5 from the interior mirror connects to the black wire on the Audi door mirror glass

5. The contacts for the Audi heating elements are larger that the
Golf ones. Replace the existing spade connectors with larger ones, and
the job's done!


Night time pics were very difficult to take, and I've had to compress the videos a lot to get them down to a reasonable size

The autodimming side mirror in action in daylight:

And at night. You get the idea...


1,885 Posts
Well done and thank you p8080 for the effort you have put into a great guide. This mod is going straight onto my 'To Do' list.

Whilst the glare from lights reflecting in the door mirrors doesn't bother me, it does bother Mrs Bora Boy quite a bit so she'll be very pleased when I get it done [Y]

440 Posts
hmmmm v.interesting mod!!

im probabily going to stick with my normal size mirrors so might have to keep an eye out for some auto dimming side mirror glasses and hitch my rear view up to this following this guide [;)]

how much do the mirror glass go for?



265 Posts
I take it that it's possible to fit a dimming rear view mirror a golf that doesn't have one?How do i go about wiring it up etc?

THis has probably been asked loads of times before so sorry if i'm being a numpty!

Any help fellas please?

363 Posts
[quote user="veedub1976"]

I take it that it's possible to fit a dimming rear view mirror a golf that doesn't have one?How do i go about wiring it up etc?

THis has probably been asked loads of times before so sorry if i'm being a numpty!

Any help fellas please?

[/quote]Just seen a post about how to wire auto-dimming mirror so there is one on here m8!
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