Instrument cluster gauges intermittent fault C180 (1994)

[Dec]

Hi all,
The gauges on my instrument cluster only work irregularly, some work some of the time while others don’t work at all, the fuel gauge in recent months and more recently, the speedometer have displayed the symptoms described below, now all 4 gauges are giving trouble every day.

Temperature needle shows cold (engine hot)
Speedometer needle doesn’t move up to relevant speed
Rev counter needle reads zero at tick over and at any driving speed
Fuel gauge reads empty (tank halve full, orange light off)

After 10 or 15 minutes driving the above instruments would spring up to their normal positions, not all at the same time but individually, eventually all would be working as the should
All other components of the instrument cluster work fine (dimmer/bulbs/clock/milage etc)
I checked the battery and fuses, the are o.k.
I was wondering if anyone had a similar problem and what was the outcome,

Thanks
Dec

 

[Shude]

The cable could be hanging out of the back of the instrument cluster, or it could be a faulty cluster I suppose.

 

[Laters]

It could be that the needles are sticking to the pins that they sit on at rest.
My speedo was the main one to do it but I cleaned all the needles/pins and the problem has never returned.
http://mbclub.co.uk/forums/showthread.php?t=15182

 

[Dec]

Thanks Shude will try wiggling cable behind dash as this is the simplest idea first.
Quantum probably has identified the problem correctly will let you know how I get on and thanks for the link, much appreciated.

Dec

 

[Shude]

I've never heard of the needles sticking to the pins before, sounds ridiculous but if it's happened to someone before then I'm willing to believe.

The needles in my car don't get chance to glue themselves down, they spend most of their lives in the halfway position

 

[Dec]

Shude, I agree, sounds ridiculous but it is plausible the needles do swivel on a watch type coil spring which is attached to some kind of resistor and the act of cleaning and disturbing them might just solve the problem.

Anyway the problem is too erratic to be electrical unless maybe as you suggest it is a loose cable, will be working on it tomorrow.

Dec

 

[shandy]

If your gauges are sticking try giving the dash a hard slap on the top when you are driving,if the needles then spring up it is probably a faulty connection.
Try cleaning the plugs on the back of the dash with an electrical contact cleaning spray.
Remember that you should not switch on the ignition with the dash disconnected as you will cause an SRS fault to register requiring the code to be cleared.

 

[Dec]

Thanks Shandy for the advice re; ignition/SRS , I did give it a slap and it did cause the speedo needle to pop up alright but had no effect on the other faulty gauges.

Dec

 

[shandy]

Try cleaning the plugs and sockets on the back of the dash with contact cleaning spray.
If that does not work the problem must be static electricity holding the needles on their rest pins until there is enough power in the gauge to release them ;this will be more evident in warm dry weather. In this case you need to split the dash to gain access to the front of the gauges,clean all areas with an anti-static cloth and as a last resort ,slip a piece of very fine rubber tubing on each of the rest pins,hopefully it won't come to this as it's a very fiddly job.
Hope this helps and you manage to solve your problem.

 

[Dec]

Problem solved

I solved the problem! I made up the 2 wire hooks and proceeded to remove dash, it was a bit tight on the left side so I thought a good yank would do it, now bearing in mind these things are quite brittle. I thought I should proceed with caution, well I still gave it the good yank, the hook slipped and tore a big chunk out of the glass.

Looking on the bright side I can now get my finger in to have a fiddle with the needles as I drive.

Will have to get a new dash €871 or a second hand €? given the year of the car a second hand will be best option. MB dealer tells me I can put in a second hand dash myself but will have to go to one of those “mileage clockers” to match up the mileage of the original dash.

Thanks all for all your help.
Dec

 

[Shude]

Bit late now but you could have pushed the instrument cluster from behind, no hooks required!

 

[shandy]

Not sure but i think i remember a mention of a replacement glass for this panel , check with the dealer.

 

[Rob77]

Is this any good to you? (Edit - I think it reads in Kph so no use)

http://cgi.ebay.co.uk/Mercedes-C-cl...ryZ10398QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

If not, instrument clusters pop up regularly. I got one for a W124 for something like twelve quid.

 

[Dec]

Yes Shude I should have pushed the instrument cluster from behind but I was too lazy to unscrew the knee panel.
Shandy re; replacement glass, thanks will look into that tomorrow

Anyway I went back to the problem this afternoon and eventually removed the dash, dismantled it and found that Quantum’s answer to the problem is correct all the needles were sticking to there pins because the black paint on all the pins was tacky/gooey, I could feel the needle sticking to the pin when I moved it.

Rather than cleaning the needle and pins, I scraped the black paint from the side of the pin that is in contact with the needle exposing bare metal and scraped the part of the needle that was in contact with the pin. All the needles on all the gauges are now working perfectly.

As to why a needle should stick to a pin in such a clean environment as an enclosed dash sounds ridiculous, I can only guess there is some kind of chemical reaction between the plastic needle and plastics in the paint to cause this stickiness.

Now if only I can find a broken dash with the glass intact I can then marry it up to my now good dash.EDIT; GOT ONE TODAY FOR £20

Dec
Edit; Rob the wiring on back is different,thanks anyway

 

[shandy]

Glad you solved your problem,i was always led to believe it was static which held the needles on the stops,now i know what the problem is, thank you. Hope you manage to source a replacement glass or front section.

 

[Thmsshaun]

Needle was stuck on my C180. Could be a 202 thing but cleaning the pins worked.

 

[1998K]

Needle was stuck on my C180. Could be a 202 thing but cleaning the pins worked.

yes, may be it's a common problem on W202, I found this "factory solution", quite strange and interesting :bannana:

http://216.239.39.104/translate_c?h...ttp://www.motor-talk.de/f73/s/&hl=en&lr=&sa=G

 

[shandy]

Good guide if you can wade through the poor translation . So thats where you get the small rubber tubes i mentioned ,they are a MB part.
" expenditure of time - 5 minutes" , these guys must be very efficient ,it takes me at least 30 mins all in.

 

[1998K]

So thats where you get the small rubber tubes i mentioned ,they are a MB part.

only to point out that I'm not the guy you are referring.

Fortunately my W202 nevere suffered from this kind of "stick" problem

 

[Dec]

Shandy
whats all this about rubber tubes, I cant read German, could you enlighten me
Dec