Signum mirror not dimming

Now it is getting darker, I have just noticed that my dimming rear
view mirror has stopped dimming, and the little yellow spotlight on
the gearstick is not illuminated. I have 2 possible sources for the
fault that occured in teh lighter months:

1) New windscreen fitted, possibly connector loose or wire snipped.
2) Software update, mechanic turned option off.

The thing is, the rain sensors still work, so is number 1 possible
(connector on at an angle or 2 connectors)?

So, has anyone had a software update and found the dimming function
stopped working, or does anyone know of any common mistakes by the
window fitting blokes?

Also, how do you open up the lump behind the mirror for me to check
for number 1?

TIA

Bob

 

Bob
The lump behind the mirror is in two halfs split vertically around the
mirror stem. Its only cliped together. Mine can fall off if I clean the
windscreen too vigoursly!!
Check that the connectors have been fitted correctly.
Dave

 

Where are the clips - I don't want to start gouging it with a screwdriver to
find I am in the wrong place.

I am leaning towards windscreen fitter incompetence - the trim on the
outside of the pillar next to the windscreen has a few tabs broken off, so I
had to put sticky foam tabs behind it.

Bob

 

You dont need a screwdriver to prise it off, fingernails are enough.
The clip is about halfway down the front (I think).
If the windscreen fitter broke some trim then you should have jumped up
and down and got him/them to pay for a new replacemnt part and fitting!
Dave

 

I only noticed a few months later, and the fix is fine. If this is not an
easy fix, I will get on to them. I am not spending £100 - £200 for a new
mirror unit. they will probably deny everything of course.

Bob

 

I got Autoglass out - can't find nything wrong with the ribbon cables. He
got the ultrasonic panel off just above it, and the ribbon was fine that
far.

Is it possible the ECU (I also noticed changes in the trip computer)
software "update" was a downgrade?

Bob

 

It was a fuse, and they didn't charge me!

Thanks for the replies.

Bob