As the dark nights start to draw in, or more importantly the morning commute in the dark, I'm finding myself dipping the rear view mirror to avoid the numerous following cars with head lights pointing up, left, right, anywhere but straight. Maybe i'm getting old, maybe i'm just starting the journey earlier with tired eyes, maybe its the result of modern, brighter head lights.

I need a fix. That fix is the auto dimming (photochromic) rear view mirror retrofit. This is the first retrofit I've done of a factory option that wasn't pre-wired. There are a number of other threads on this topic, but non where sufficiently detailed to just get on with it, so I'm sharing my learning to help the next modder!

So this is the mirror, you can see the Tyco 8 way GET series connector



Along with the auto dimming function, this mirror also has a humidity sensor/ ambient temperature and glass temperature sensor which connect to the HVAC controller by LIN bus. With these three sensors the HVAC can calculate the dew point of the air and calculate when the screen is likely to mist, and do something about it, hopefully.

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Not much help... I have a 5% tint on B pillar back never had to dip my mirror ever! MY14 Kahn Converted Dynamic - Fuji White Ebony/Pimento Interior
MY15 Xenon Headlight Conversion

MY17 RRS SVR - Estoril Blue Cirrus/Ebony 🪣💺’s

ive found that having factory spec rear window tints almost negates the need for an auto dimming mirror, my HSE's barely ever dipped as far as I noticed,

Hi,

Same for me as RogB my tints mean I have also never noticed my mirror change at all, I am however really interested in your pics and I must thank you as my mirror fell off last winter and the little round sensor thing got damaged. I had no idea what this was and couldn't find out, it didn't seem to change any of the functions so I just forgot about it until I read this feed.

I now need to see if this is something that can be found separately or I can find a mirror with it attached on the old fleebay.

Thank you for a good little how too which I'm sure people will use. If your going through hell, keep going!

Wrapper of rear pillars 😀

If your going to so much trouble to put it in then why not add a USB supply for a dash cam (or something similar)
as I did.
http://www.freel2.com/forum/topic31504.html

Well, I am rather impressed!

Being an older design the mirror does tend to over dim ( compared to more modern LR products and competitors) and can sometimes be a little slower to clear, but it's certainly fast to react. Didn't have a single misaligned headlight bother me on the way to or from work. Even works with high levels of solar on the rear.

I have pics for a few other useful pointers that I need to upload.

I take your point about the tints. They trouble me though. I spend a huge amount of time in premium SUVs and saloons of all types, and as they all have tints they all feel a bit cave like. I bought DIY tints when I got the car 2 years ago, still in the roll. Been and got a quote from a man, was a fair price. Still no tints. Something I like about the FL2 is how open the cabin is. Would tints ruin that? Does a lack of tints mean the children see more of the world?

DEG5Y,
I already had a USB feed to the mirror for a dash cam. But I agree if some one is going to this length, they should seriously consider running the extra cable.

To save boring anyone with installed condition pictures, I'll post just one more.

This is the location of the second connector which has the pins for the supplied power and the reverse light feed which turns the dimming off immediately when you enter reverse.

Click image to enlarge

Thanks Vanny, be wanting to locate 39D/39C and I can even see the WH/RD wire going in and not going out you’ve just saved me a subscription to Topix
By any chance would you have pin information for this plug or the info on this plug from Topix?
Did you enable the humidy sensor? Damp Sensor? MY15
Tyre Pressure Monitoring System (TPMS)
Surround Camera System
InControl Apps soon to be replaced with CarPlay (WIP)
Meridian Premium Surround Sound
Digital Audio Broadcast
Timed Climate
Cruise ECO Data
Follow Me Home Reverse
Extra Features Menu
Picture In Motion
4x4i screen (WIP)
Digital Broadcast TV
Meridian Rear Media with WIFI
Factory Powered Tailgate
Blind Spot Monitoring (BSM)
Reverse Cross Traffic Alert (RCTA)
Electrochromatic Wing Mirrors (WIP)

Believe it or not I haven't put the laptop near the car since this post so no, its not enabled yet. Been busy.

I sort of just figured out what pins should be on both sides by searching for "39C" in the wiring diagram, then made up the harness to the lengths in the diagram, fed it through to the dash then it gave me an idea where to look. All very heath robinson/inspector clueso but it worked, I found the right coloured wire in the matching connector with nothing coming off it, and the wires around it matched the colour codes.

I guess it worked as the mirror dimming drops in reverse as expected.

Well, only a year and a half later, but I finally changed the CCF to allow the humidity sensor to function!





As it's connected by LIN directly to the HVAC, and warm outside, it's pretty hard to know if it's worked and if this is the right CCF change. But come the winter I'll be sat out it the car with a coffee under the sensor to see if it make the blindest bit of difference to the HVAC operation!

Hello Vanny,
I am on the quest to upgrade my rear view mirror to the version with humidity sensor, My car is SE with auto dimming mirror (I believe ) and rain sensor, I have attached pictures below.
Will this be a case of just installing the new mirror with the humid sensor and activating damp sensor in CCF or I need extra wiring? How will I know if I need extra wiring to make the humidity sensor work?
Many Thanks. Regards,
Germplus.

2008SE
Memory seats
Webasto Fuel Burning heater with smart phone remote start
Premium Surround Sound
Xtron Unit with wireless CarPlay
Dual Battery System
DAB

I have to say, I didn't realise there was a version of the mirror with dimming but without the humidity sensor. I was fairly convinced if you had one, you had the other. Do you have the grills on the back?

As the humidity sensor connects directly to the HVAC, you would need to run the wire so that the humidity sensor has an impact on what the vehicle does.

Hello Vanny,

Thank you for the reply. I picked up a used rear view mirror with humidity sensor and all the connector plug was there on my car( pre-wired). I forgot to count how many wires but will say about 8 all colour coded. I can remember the green and other colours. After that I changed the ccf with iidtool bt to damp sensor fitted similar to your your post. drove around for a while and checked error code but there was none, so I'm assuming its all working.I checked the live values of humidy and windscreen temperature after fitting but didnt get any values. Maybe I ws reading the wrong data 😂. Will keep an eye for a change in the HVAC behaviour on my up coming road trip from southwest of UK to Germany.Hopefully its all good. once again thank you for the information. Regards,
Germplus.

2008SE
Memory seats
Webasto Fuel Burning heater with smart phone remote start
Premium Surround Sound
Xtron Unit with wireless CarPlay
Dual Battery System
DAB

Best way to check the humidity sensor is to stop at a greesy spoon, order a bacon butty and a piping hot tea, and eat them in the car!

That will ramp up the humidity to trigger the HVAC response. It will initially put more air to the screen and possibly turn the heated windscreen on if you have one.

 Regards,
Germplus.

2008SE
Memory seats
Webasto Fuel Burning heater with smart phone remote start
Premium Surround Sound
Xtron Unit with wireless CarPlay
Dual Battery System
DAB