[Mscott6912]

I cannot see the 2 larger needles at night. Small ones (e.g. fuel) are ok. 2011 R171

Any ideas?

 

[jbanks15]

have you undimmed them with the buttons on the side of the console binnacle?

 

[jbanks15]

 

[Mscott6912]

If the needles can be dimmed independently of the numbers around the guages then no. I could not see any way to do that in the manual I have been referencing (car didn't come with a manual).

 

[jbanks15]

so you talking tach and speedo needles are too dim but others are ok?

 

[jbanks15]

so you have tried to use those buttons to adjust brightness of dash?

 

[Mscott6912]

I can see the fuel gauge and clock just fine at night, just not tacho and speedo needles. The numbers can go dark or bright using the buttons.
Did not seem to change the needle lighting.

 

[jbanks15]

humor me
are you checking in a dark garage or outside when dark?
are your lights on position 2 or auto?
has it ever worked right?

 

[jbanks15]

The light sensor is located here.

Location: Sensor is located inside the blackened area where the cockpit rear-view mirror anchors unto(when looking at the windshield from outside the car). Interior lighting - All the lights on the inside of the car and on the doors, so that’s the overhead lights, the puddle (courtesy) lights...

www.slkworld.com

clean this sensor...

The 'Instrument/switch gear' light sensor is...

From John (UK-C200) - There are two light sensors, one on the windscreen behind the rear view mirror, that controls the headlights. There's another in the middle of the cluster, between the two pieces of the MFD, that's used to adjust the interior light levels - when the exterior sensor says...

www.slkworld.com

 

[Mscott6912]

I will try to clean those sensors.

When I have fiddled with it, it has been dark, otherwise I don't notice.

Typically I have the lights set to auto but others have driven the car.

To be honest I don't know for sure they ever worked. I bought it during early 2020 the owner has passed away. For a long while I wasn't going hardly anywhere, let alone at night.

 

[Mscott6912]

Here are 2 shots of the speedo part of the dash with a tarp over the car. One has full dim and the other full bright.

The needles for the clock as well as numbers change in brightness using the buttons, but the needle on the speedo does not change.

It is the same situation for tacho/gas.

 

[jbanks15]

@Sneaky Pete
@efair
@i860

 

[jbanks15]

check fuse 30 and 51... instrument cluster for giggles

R171 Fuse and relay locations and pics and descriptions

http://www.billsden.org/fileadmin/media/mercedes/slk/docs/train_fuse_locations.pdf Also, good to know ground points. See Ground points on the car body >>>Additional Ground Points thread

www.slkworld.com

 

[Mscott6912]

Both fuses are ok. Pulled them they aren't open and put them back. No change.

I also have a mysterious red led on the door lock that flickers at times. If I understand things, it is related to the alarm, but why it flickers sometime I don't know.

A few months back I had a bad battery and lots of weird things were happening.

Now in the winter here (Vancouver) it sometimes gets crazy moisture inside if I am not running it regularly.

As there are no obvious things, I am thinking that there is some corrosion somewhere.

I am guessing I would need to open the dash next, but if that is the case, I will stop for now. I have no room in my garage for prolonged work.

I can use the digital speedo and I don't need to see the tacho.

 

[jbanks15]

ahhh so you still have a 'bad' battery? was it replaced with new?

 

[Mscott6912]

I 'had' a bad battery, now I have had a new one for a couple months.

 

[efair]

I have no idea what's wrong, but It's very simple to remove the instrument cluster, no other items besides the two small trim panels need to come off.

 

[Mscott6912]

Ok, thanks. Maybe I will look around for instructions and try that. Probably everything is within connectors, ICs, circuit boards and won't be much to see but one never knows...

 

[Alex 3]

If the needles can be dimmed independently of the numbers around the guages then no. I could not see any way to do that in the manual I have been referencing (car didn't come with a manual).

You can find manuals online. I keep the OEM one in the car down in our parkade so I have a PDF of the 2009 SLK in my computer.