Rear view mirror

[Stuntman Mike]

My mirror on my c class has stopped dimming it only dims sometimes can some on tell me if its broke or can it be fixed

 

[whitenemesis]

If you could elaborate a bit..

When does it dim?

Does the door mirror dim?

 

[Stuntman Mike]

Sometimes it dims but very rearly when the mirror is working so does the door mirror work. It all works 4 a few days then it will stop working 4 a day or 2

 

[whitenemesis]

If the dooor mirror only dims when the RVM dims then it sounds like the sensor has gone faulty in the RVM.

I don't think one can replace the sensors, so a new RVM needed.

 

[crockers]

Have you tried holding your finger over the sensor?

 

[Stuntman Mike]

Yes i done that on the sensor on the back off the mirror and it worked so i think the sensor on the back is couseing the problem.

 

[mr. shr]

If the dooor mirror only dims when the RVM dims then it sounds like the sensor has gone faulty in the RVM.

Surely this is correct operation?

I thought the door mirror will ONLY dim when the RVM dims.

I.e. when the sensor in the RVM detects headlamps from behind, it dims the RVM and sends a signals to the door mirror to also dim.

 

[whitenemesis]

If the dooor mirror only dims when the RVM dims then it sounds like the sensor has gone faulty in the RVM.

I don't think one can replace the sensors, so a new RVM needed.

Surely this is correct operation?

I thought the door mirror will ONLY dim when the RVM dims.

I.e. when the sensor in the RVM detects headlamps from behind, it dims the RVM and sends a signals to the door mirror to also dim.

You are perfectly correct.

What I was (rather ineptly) trying to say was if the door mirror dims and the RVM didn't it would be the RVM glass, or the signal to it, that was at fault. But as they both worked - or didn't - it must be a (intermittent) fault with the sensor....

 

[andy27168]

Hi,
It could be an intermittent fault with the overhead console which is where i believe the mirror is plugged into, before buying anything new i would get it plugged into STAR as this overhead console communicates to the diagnostic system and may have logged a fault especially as the mirror is inoperative more than it is operable.

 

[2phast]

On the STAR system, you can program the overhead control panel (ocp) and tell it what kind of glass you have, factory tinted or non-tinted. I played around with this a bit on my CLK and the wrong setting can cause the mirror to dim in daylight (when it shouldn't dim). Also the OCP, if defective can cause intermittant problems with the dimming functions of the mirror and door mirrors.

Probably best to have someone do a diagnostic via the STaR system, its pretty good at catching these problems.