2004 C5 LX
Finally got everything working, but it was a trial. The mirror was not straightforward as the fitting on the screen for the standard manual dimming mirror is different to the auto-dimming mirror! I had to replace the screen anyway as it was cracked, so I went to my local friendly screen company and they ordered the correct screen with the cut-out for the sensor. All the wiring was in place for both mirror and sensor.
So, as far as the mirror is concerned, unless you're prepared to change the screen, you might want to consider an aftermarket version which will fit the existing bracket like this one:
http://www.ebay.co.uk/itm/Auto-dimming- ... Swo6lWQvzw
The rain sensor baffled me for a while. I installed it with a gel pad, but although it was activated with Lexia and the ECU was being recognised and the message came up on the display that automatic wipers were on, it didn't work.
I checked through the archives and spotted this little nugget from 2006:
http://www.frenchcarforum.co.uk/forum/v ... 00#p127500
pugxpert posted this:
Luckily, I had another gel pad and as soon as I added it, the thing sprung into life! The windows automatically wound up too! Thank you pugxpert.check where sensor fits the screen,if it defaults every 4.5 seconds this could be the problem,if screen is cracked across sensor the light prism bounce off the crack default is then 4.5 sec ,also check on sensor should be 2 gel pads in sensor,if had screen change these can stick on the old screen
Yet again, the forum has provided the answer! I hope my experience might help someone struggling in 2026.....
Cheers
David