Auto Dimming Rear View Mirror

[richardch]

:( For no apparent reason but I need this now its winter and I drive to and from work in the dark. The green auto light works on the mirror but the light sensors don't work, could this be a fuse, has anybody else had this issue or had any suggestions ???? HELP !

[richardch]

:( For no apparent reason but I need this now its winter and I drive to and from work in the dark. The green auto light works on the mirror but the light sensors don't work, could this be a fuse, has anybody else had this issue or had any suggestions ???? HELP !

<{POST_SNAPBACK}>

nobody hasexperienced similar >>???=>

[richardch]

Nobody else has experienced this issue ????? or knows how to sort

[Loren]

Please do not repeat posts ever 10 minutes.

The anti-dazzle mirror (interior and exterior) are on the same same fuse (B5) as the backup lights, rain sensor, and door mirror adjustment.

[richardch]

The anti-dazzle mirror (interior and exterior) are on the same same fuse (B5) as the backup lights, rain sensor, and door mirror adjustment.

<{POST_SNAPBACK}>

Apols for the duplication Loren, B5 fuse is ok, could the light sensor have failed, can you dissemble the mirror unit ?

[Loren]

Does the drivers side (exterior) anti-dazzle mirror sensor work?

They both trigger off the same sensor in the interior mirror.

[richardch]

Does the drivers side (exterior) anti-dazzle mirror sensor work?

They both trigger off the same sensor in the interior mirror.

<{POST_SNAPBACK}>

Nope Loren on both mirrors (rear and driver) anti dazzle is out; but I have power to the rear view mirror (auto light goes on and off) and my rain sensor and reverse gear mirror function both work. I have a GT3 seat installed but was very careful to reinstall all the necessary connections to the control box. I went through all the fuses in the box they are fine and have no warning lights

[Loren]

Well there is definitely wiring for the mirrors under the drivers seat. Did this happen just after installing the seat?

Here is the proper way to test the sensor:

1. Ignition on.

2. Cover photocell on the glass side of the interior mirror; the mirror surface must darken after about 4 seconds. Uncover the photocell. The mirror should brighten within approx. 6 seconds.

3. Repeat, except that before uncovering the photocell, ensure the mirror goes from a dimmed to an undimmed state when reverse gear is selected.

[richardch]

Well there is definitely wiring for the mirrors under the drivers seat. Did this happen just after installing the seat?

Here is the proper way to test the sensor:

1. Ignition on.

2. Cover photocell on the glass side of the interior mirror; the mirror surface must darken after about 4 seconds. Uncover the photocell. The mirror should brighten within approx. 6 seconds.

3. Repeat, except that before uncovering the photocell, ensure the mirror goes from a dimmed to an undimmed state when reverse gear is selected.

<{POST_SNAPBACK}>

Loren; I have no exact idea of when it happened except I know it doesn't work now and I did switch the drivers GT3 seat in June, only when the seasons change is it obvious as I go to work at 06.30 and returm from 18.30 and otherwise don't drive in the evening. I have tried covering the photocell on the glass side and there is no difference whether the rear view mirror is auto on or off, covered or not but I guess the passenger mirror wouldn't swivel in reverse had I not reinstalled something correctly in the control box under the seat ( which it currently does). I really appreciate your help here by the way....

[Loren]

I want to have a look at the schematic.

What year TT and US or RoW?

[richardch]

I want to have a look at the schematic.

What year TT and US or RoW?

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ROW May 2001

[Loren]

The sensor is on the yellow (+) and green (-) wires so you could try it out of the circuit and see if the resistance changes.

This could also likely be tested with a PST2 but I don't have a car with anti-dazzle handy.

[richardch]

The sensor is on the yellow (+) and green (-) wires so you could try it out of the circuit and see if the resistance changes.

This could also likely be tested with a PST2 but I don't have a car with anti-dazzle handy.

<{POST_SNAPBACK}>

Loren strangely I've discovered both anti-dazzle units WORK with either the passenger door open or the interior light on, what does this mean ?

One obvious solution would be to leave the drivers side interior light on and take the bulb out, I've tried that but it obviously needs the bulb to work

Edited October 9, 2005 by richardch

[Loren]

Hmm... either shorted or miswired?

Were the anti-dazzle mirrors installed at the factory or after?

[richardch]

Hmm... either shorted or miswired?

Were the anti-dazzle mirrors installed at the factory or after?

<{POST_SNAPBACK}>

Loren Its OEM factory install, never had a problem, seems to be an earth problem ? all the interior lights work; could I just "inactivate" one put leave it plugged in and yet permanently switched on to get the anti dazzle units working

[Loren]

Has anybody wired in a radar detector to that circuit?

I would open it up and look for a loose or shorted wires.

[richardch]

Has anybody wired in a radar detector to that circuit?

I would open it up and look for a loose or shorted wires.

<{POST_SNAPBACK}>

Nope but will have a look Loren for any loose wires

[richardch]

Loren I'm back on this issue, its been such nice weather in Europe I've been driving the Ferrari most of the time.

I can't find any loose wires and so am thinking of taking the bulb out of the drivers side interior light ( not the main central interior light ) and shorting the connection, as this seems to work perfectly with the bulb in ( but the light on ). Any advice on what grade wire or tin foil etc that I can short the bulb socket connection with ??

[Loren]

I would use the same (stranded) gauge as what it already up there.

Seems like a good workaround - but still puzzling :rolleyes:

[richardch]

Loren, with whatever guage wire I use it blows fuse C3

This is very frustarating as I know the dimming mirror works perfectly when the interior light is on, I have

1) Taken out and inspected the interior light unit, which is mostly hard circuit wired anyway and see no problems.

2) Re inspected the control box beneath my now GT3 seat and everything is fine there too.

Its almost as if its just missing a positive feed ( hence one of the interior lights needing to be on to make the mirror dim )

Any other thoughts from your end Sir ?

[Loren]

About the only thing I could think of would be to trace the installation and see if it was done right. The TSB for the auto dimming mirror(s) is in the Contributors only view of Current TSBs.

[NeverFastEnough]

When reading this post I am wondering why my auto-dimming mirrors have also decided not to work.

I had the mirrors installed by the dealer as an option (not from the factory) and I do remember they had a heck of a time getting them to work right. If I recall they had to get in a "special wiring harness" and even then it seems like it was a royal pain in the a** to get them to work properly.

Since then I have installed GT3 seats and I am wondering if in so doing have made the auto-dimming mirrors non-functional. As those who have swapped their seats out know, underneath the drivers seat there are 2 "black boxes"...one attached to the floor and on attached to the seat. After a seat swap the one on the floor obviously stays but the one on the seat goes.

My questions are therefore:

Is the little black box attached to the drivers seat needed for the dealer-installed auto-dimming mirrors?

If so is there a way to bypass it?

Am I out to lunch and there may be another reason why the mirrors have mysteriously stopped working?

Any help would be greatly appreciated.

Edited November 24, 2005 by NeverFastEnough

[richardch]

When reading this post I am wondering why my auto-dimming mirrors have also decided not to work.

I had the mirrors installed by the dealer as an option (not from the factory) and I do remember they had a heck of a time getting them to work right. If I recall they had to get in a "special wiring harness" and even then it seems like it was a royal pain in the a** to get them to work properly.

Since then I have installed GT3 seats and I am wondering if in so doing have made the auto-dimming mirrors non-functional. As those who have swapped their seats out know, underneath the drivers seat there are 2 "black boxes"...one attached to the floor and on attached to the seat. After a seat swap the one on the floor obviously stays but the one on the seat goes.

My questions are therefore:

Is the little black box attached to the drivers seat needed for the dealer-installed auto-dimming mirrors?

If so is there a way to bypass it?

Am I out to lunch and there may be another reason why the mirrors have mysteriously stopped working?

Any help would be greatly appreciated.

You need to retain the black box under the seat for the dimming mirrors and certainly the dipping passenger door mirror in reverse, I did

[NeverFastEnough]

richardch,

thanks for the info.