Auto Dimming Rear View Mirror
 

Practically the only thing my car wasn't fitted with and its one thing I really like. What's involved in retro fitting the auto dimming mirror? Is it even possible and what is the likely cost? Help please......

Hi.

Is your car a 1994 or 1995??

Chris.



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Now playing: Bloodhound Gang - Screwing You On The Beach At Night
via FoxyTunes

2002 s8

Its not too tricky....

The autodip interior mirror has simple + 12 supply, ground and connection for reverse (so it turns off when you select reverse) - It also has an output that can be used to drive the exterior door mirroring dipping too if you want that...

Hi Ian,

Hope you're well...it's been a while...

Quick question for you - one of the first things I did when I bought my S8 nearly 3 years ago now was to buy & fit the auto-dipping mirror - well along with a switch or two to replace those boring plastic covers. :ROFL:

I never did get round to wiring in the mirror and was thinking I needed the harness for it.

Looking at your post above it would appear that I might be able to take the +/-12v from the interior light - ignoring the reverse signal of course but at least it would save me squinting when some pillock comes up behind on full beam!

Would you happen to know what colours on the auto-dipping mirror wiring correspond to +/-12v please?

Can't remember what colours are in the mirror harness but will feel a little embarrassed if it turns out to be red/black! :o

Thanks & regards,
-=Glyn=-

I'd go along with this one.......... and 'bump' it

Anyone know the wiring for an auto dip pre facelift, my 'new' mirror has 3 wires
Black with Blue trace, Brown, and Blue with Red trace, and best place to take feeds from?

Thanks

Black with blue trace = ignition + 12v
Brown = Ground
blue with red trace = Reversing feed

There is no easy place to get the feeds from in the roof as the interior lights arent ignition controlled, and the sunroof power feed is controlled by the central locking module as it works for a short time after ignition is off so that you can still close it, and it can be done from the remote.

If it were me, I'd pop off the passenger side A pillar trim and run cables up there directly from the relay box under the passenger footwell carpet. I would imagine that you will likely be able to tap the reverse feed from down there somewhere too. It will be blue/red and runs the length of the car to the boot down the sills, most likely the passenger one....

Hope that helps...

Thanks for the heads up Ian,
That's fantastic, I'll get stuck into that over the weekend. My immediate project is iPod & USB integration which I may do tomorrow if the weather's ok and the ordered parts arrive in time. (Dension Gateway 300)
I'll report back if this is successful, failing that I guess I'll be looking at possibly upgrading the head unit (something OEM Audi) not sure quite how radical to go though.....

I know it's an old thread, but did this ever work?

The lack of an auto-dim mirror on my 1998 PF S8 has always niggled!

I've even upgraded my similar-vintage Ford Focus with one which is nice; it was pretty easy - just needed to run a longish single wire to find a suitable switched 12V supply - took earth from the interior light.
(took 12V from the night-lighting connector on the back of the radio in the end as it was easy to identify and access)

It works great - my pre-facelift A8 4,2 QS had auto dim rearview mirror, however, my pre-facelift S8 didn't. I ran my feed direct from terminal 15 (via the fue / relay panel in the passenger side).

Excellent, sounds like a New Year pressie for the car....

But how easy is it to mount? :Confused:
My S8 mirror is just on a short stalk glued to the screen, which obviously I don't want to damage. :tuttut:

There's one listed by A8parts on eBay but it looks like it's mounted on a stalk:
http://www.ebay.co.uk/itm/Audi-A8-D2.../130585974107?

(electrics I'm sure I'll cope with having already done the Focus +++ )

Hi HP......
The mirror is still glued to the screen in the same way, the 'stalk' is a sort of 'conduit' for hiding the wiring to the mirror up to the headlining (felt padded) that rests against the screen.

HTH

Alcantara please. +++

Thanks for the info, Carl from A8parts said similar in an eBay message.

I think my S8's a little 'police-specced', when compared to yours :)

How is that a problem; the sunroof seems an ideal power source?
Or will it upset the module in some way.....:Confused:

No, it will probably work fine I guess. It would just bug the crap out of me knowing that I'd cut corners to wire it up, I'm a bit anal when it comes to wiring things up the 'factory way' +++

Well my nice mirror arrived today from A8Parts. +++

But it has 6 wires in the lead, including the 3 above:
Black with blue trace
Brown
Blue with red trace
Red
Yellow
Green

Any ideas anyone what Red/Yellow/Green are for?

And a very important point - how do you remove/remount it?
Looking at the end of the mounting arm it has some sort of clip, but no obvious release mechanism.

Not being able to see the "button" it mounts on I've no idea - is there a release button or fixing screw there or do you just pull or twist it off?
I certainly don't want to risk damaging the windscreen! :tuttut:

Edit: Found several comments online saying twist the stalk 90 degrees anticlockwise to unlock. Can anyone confirm before I risk cracking the screen?

Also, what's the best way to get into the sunroof control panel to get some power; it doesn't obviously come off simply so there's presumably more than clips holding it all up there.

Twist 90 degrees and withdraw to remove is correct.

The extra wires, it's been a while I fitted an auto-dim mirror to my old '98 S8. The blue with red trace is illumination (instrument illumination).

I actually fitted an auto-dim from a 2005 Audi Allroad, it had a digital compass in one corner, pretty neat. :cool:

It's about 45 dg anti-clockwise on PF cars to undo it but take care. Cannot help about wire atm

Well I've verified the 2 important wires:
Black with blue trace = ignition + 12v
Brown = Ground
And tested it works by jury-rigging the lead to a 12V DC wall-wart and covering the sensors appropriately. +++

Any thoughts from anyone on how to get safely into the overhead lighting/sunroof control area and what to look for?

I'm not bothered about the reverse feed at all; I didn't connect that on the unit I fitted to my Focus and don't ever miss it.
(tend to use windows, side mirrors, eyes and brain, assisted by the rear parking sensors :ROFL: )

Well, it turns out it's 60 degrees anticlockwise on mine - the mounting is hexagonal. :D

Once rotated to the release position it came off very easily.
I had a moment of inspiration and remembered one of my "oldies" tools in the kitchen - a "BOA-CONSTRICTOR" designed to help remove difficult lids on jars.
See: http://www.amazon.co.uk/Miscellaneou.../dp/B0001J0456 it even refers to use on cars there. ;)

It has a rigid plastic handle and a tough rubber strip that you wrap round the "lid" then feed back into a slot on the handle. Applying rotational pressure locks it firmly. Ideal for rotating the mounting pillar as it does no damage at all but gives a superb grip. +++
As they say "Every home should have one" (and every car mechanic)

Now I need to look at the power supply for the auto-dim version.
I'd still prefer to take it off the sunroof (access comments anyone) but.......
I've got all the floor mats out to dry the interior as stage 1 of dealing with the flooding, probably due to clogged evaporator drains. :(

Well it's a bright sunny day today so I can see what I'm doing. :ROFL:
Got the lights/sunroof panel off - unclip transparent bulb cover, remove 2 recessed screws by the bulb and it just unclips easily. +++
(as described in the drivers manual, as I've just discovered :o )

But inside it, ignoring (for now) the wiring for the phone (mic) and sunroof controls there's a 5-core multicoloured lead to the interior lights. :Confused:
(there's also a thin, I think red/black, lead that meanders around with no obvious function/connection - sun visor mirror lights probably)

I'll post up the colours shortly, but meanwhile I'm going to have a bit of an "investigate" with my multimeter on the interior light connection.
Logic says you only need 3, not 5 - 12V, 0V and door open. :(
(Unless anyone knows what they're all for and can save me the effort. :love:

Edit: The colours, from left to right are:
Red with blue (or purple?) trace
Green with blue trace
Brown
Brown with yellow trace
Brown with white trace

Results of investigations:The switched connectors all switch together, 12V normally, dropping to around 1V if any door is opened. Ignition/lights have no effect.
So no use for the mirror. :(

The sunroof motor is more promising however; bit tricky to disconnect due to lack of space.
Fat Red/white = 12V
Purple/black also 12V
Fat Brown = 0V
Red/yellow = 12V when ignition is on (with a retaining delay I think), 0V when doors are locked.

I don't want to disturb the "fat" heavy-duty cables to the sunroof, so I'll probably take 12V from the sunroof red/yellow and 0V from a screw (there's a couple of suitable holes in metal that test OK) or the lights (brown) using the dreaded Scotchlok's.

No doubt some of you perfectionists will be squirming in your seats now. :ROFL:

Job done, very pleased with the result. Works perfectly. +++

Biggest problem in the end was actually getting the lead from the mirror into the space above the lights to connect it up, it's a bit tight and though I could get a big cable tie through to pull with the plugs kept snagging. In the end I fed it unterminated and fixed the plugs (just bullet connectors) once in place - very little spare wire to work with though. :mad:
(I did take 12V from the sunroof and 0V from the interior lights in the end. ;) )

And proved handy just now.
Already freezing outside, headed off to the station (3+ miles) and was stuck behind a big supermarket truck at 30mph on a narrowish country road. No possibility of overtaking anywhere.

Some t**t in a big 4*4 caught us up and decided to drive as if I was towing him. :mad:

Glad to see you got it working well. +++

At some point, I'd like to replace mine with one from the C5 Allroad (probably on other C5 models). There was the digital compass option, pretty cool. :cool:

A couple of things I've noticed after rather more use:
1. The interior lights coming on (e.g. dropping off a passenger) make it go very dark very quickly. If you're using the interior mirror to check behind before moving off you need to wait briefly.
2. In the (admittedly very rare) situation of someone overtaking you on the motorway at night the darkest is actually as they get close and move out of your view. I think this is due to the direction the rear-facing sensor points in, i.e where the mirror is pointing which is obviously half-way between rearwards and towards your eyes, so significantly to the offside.

Oddly I haven't noticed either of these effects on the similar mirror in my Ford Focus, though the rear-facing sensor on that is recessed below the mirror rather than behind the top of the glass. And being a hatchback there's probably more bodywork blocking light from overtaking vehicles. (it also has a handy "off" button)

^^^ Interesting observation, HP.

This brings me to another issue - how do those with really dark tints on the rear (sometimes limo tint on the rear screen) fare with auto-dim (or rather lack of?) Because one could argue the rearview mirror doesn't suffer from as much "glare" as would be achieved with a stock rear screen.

But that means the door mirrors won't dim either. Has anyone with dark rear windows suffered "glare" from their door mirrors as a result of the photo cell seeing less light from the rear?

Personally I've never really found glare from the door mirrors to be an issue on any car I've ever owned.
(and none have ever dimmed, just the interior one as on both my current cars)

Rear window tints will affect the accuracy of the auto dip mirror.

In the owners handbook, Audi even say that using the factory rear blind will affect the auto dip mirrors (where fitted)... +++