W169 rearview mirror permanently dimmed

[Albee777]

Any advice on fixing a rearview mirror permanently dimmed when ignition is on

 

[ZZZZ]

Is the light sensor obstructed by any chance?
It's on the back (i.e. the forward facing cover).

Welcome to the forum

 

[ZZZZ]

I don't have pictures of my own mirror's back, so here's one from eBay:

If the sensor is clear of any obstruction, and clean, then check the connectors (the yellow one here) and wires for damage, and maybe clean plugs with contacts cleaner:

In the mirror assembly:

And inside the OCP (the one on the right, with pink, brown and blue-yellow wires):

 

[Albee777]

I don't have pictures of my own mirror's back, so here's one from eBay:

If the sensor is clear of any obstruction, and clean, then check the connectors (the yellow one here) and wires for damage, and maybe clean plugs with contacts cleaner:

In the mirror assembly:

And inside the OCP (the one on the right, with pink, brown and blue-yellow wires):

 

[Albee777]

GLK Thanks for your prompt reply. Just installed a dash cam and didn’t realise mirror had sensor on back. Have relocated dash cam and problem solved. Much appreciated.

 

[ZZZZ]

Excellent! Always great, when it's an easy fix to a problem.

 

[davemercedes]

Thanks for this post. It's my intention to install a dash cam in the next week or so and just behind the mirror is the obvious place for it. doh!

 

[ZZZZ]

Yep, one of the reasons, mine is on the passenger's side ...

Which reminds me - it's over six years old now, so I ought to start looking for a replacement.

 

[Albee777]

Thanks for this post. It's my intention to install a dash cam in the next week or so and just behind the mirror is the obvious place for it. doh!

Yep, one of the reasons, mine is on the passenger's side ...

Which reminds me - it's over six years old now, so I ought to start looking for a replacement.

 

[Albee777]

The problem arose when I fitted the dash cam to the right of the mirror. Fitting to the left is no problem except that space is a bit tighter. Still it makes the cam less visible from outside. There are some nasty people around who would have it away if they spotted it. Also I covered the shiny bits with black tape. Paranoid? No.

 

[davemercedes]

The problem arose when I fitted the dash cam to the right of the mirror. Fitting to the left is no problem except that space is a bit tighter. Still it makes the cam less visible from outside. There are some nasty people around who would have it away if they spotted it. Also I covered the shiny bits with black tape. Paranoid? No.

Paranoid?
No, sensible, I think.

These days, infortunately there's not too much you can do to prevent your vehicle being tampered with - short (pun intended!) of loading all metal bits with 100,000 volts and you can be done for that - and I think somebody was (?)! Worse still, if you zapped a thief/yobbo doing damage, you'd end up paying him compensation. And who says the law is an ass?

 

[ZZZZ]

I actually modified my BlackVue DR400G-II quite heavily - perhaps that's why it is still working perfectly fine, six years on.

I removed all the chrome bits, including the lens surround (built my own); modified (slimmed down) the holder; fitted a permanent CPL; drilled four (or was it six?) holes for better ventilation; blackened out side button LED; and finally, wrapped it in carbon fibre vinyl, including the holder.

It's hardly visible from the outside, and as I said - worked perfectly fine in my old car since Spring 2012, and now for over three years - in the current car.

 

[davemercedes]

I actually modified my BlackVue DR400G-II quite heavily - perhaps that's why it is still working perfectly fine, six years on.

I removed all the chrome bits, including the lens surround (built my own); modified (slimmed down) the holder; fitted a permanent CPL; drilled four (or was it six?) holes for better ventilation; blackened out side button LED; and finally, wrapped it in carbon fibre vinyl, including the holder.

It's hardly visible from the outside, and as I said - worked perfectly fine in my old car since Spring 2012, and now for over three years - in the current car.

Well fingers crossed, it will stay like that! Whatever you do, if it's working, don't fix it!

 

[PHUNN]

On the topic of dipsey mirrors (well not too off-topic I hope...) does anyone have a remedy for an unwanted tendency for severe automatic dimming during a combination of roof down/low winter sunshine cruising?
Recently, driving East, enjoying a lovely evening on the M4 my mirrors were virtually black. Can their 'dimming' function be disabled by the driver I wonder? (No. I did NOT decide to go quick enough, to reduce any danger, to the point that there would be no possibility of anyone catching me up!!)

 

[ZZZZ]

You could fit a small LED near the sensor, with a switch hidden, say in the power socket tray - to compensate the direct sunshine from behind?


PS The only way to turn off the function, as far as I know, would be to cut the power to the mirrors, or the sensor, and that would bring up all kinds of hissy fits by SAM.

 

[PHUNN]

SAMs no like snippers methinx.
I remember having this dimming problem with an SLK 172 after Merc resprayed it... (but that's another story altogether) and thought the problem stemmed from their dismantling/re-building efforts.
Maybe it's 'a product feature'.
Let's face it, the problem arises all too infrequently in our climate.

 

[keefysher]

On the topic of dipsey mirrors (well not too off-topic I hope...) does anyone have a remedy for an unwanted tendency for severe automatic dimming during a combination of roof down/low winter sunshine cruising?
Recently, driving East, enjoying a lovely evening on the M4 my mirrors were virtually black. Can their 'dimming' function be disabled by the driver I wonder? (No. I did NOT decide to go quick enough, to reduce any danger, to the point that there would be no possibility of anyone catching me up!!)

1st world problem. Pretend you are in Italy and wots behind does not matter, FTFY