W210 Instrument displays

[Tim Green]

I have been on before about this problem whereby the temperature, clock and gear selection displays on my w210 320 CDi do not work properly. I seem to remember the problem is the connectors used for the displays. Is there an established method for removing the binnacle to get access to the displays, and what is the best method of fixing the connectors? I think I must just get on and do the job - I came back from Portsmouth in 4th gear! Also, one of the bulbs illuminating the odometer panel has gone as well - what do I need to ask for at MB garage? Any help gratefully received!
Rgds TG

 

[jaymanek]

From a thread in another forum:

If you know how to take out the cluster, ignore my droning in the first section.

Please bear in mind this was a few days ago, I've never taken a Merc apart before, I have no idea of the intricate variations, the following worked in my car (CLK320 2001 Avantgarde), if your car blows up, if you blow up or you completely wreck your cluster, don't blame me, hunt me down or hate me.

Whip out the cluster, I'm guessing you know how, I used a coat hanger, cut it in two, bent both the ends, slipped them in behind the cluster (I hate the word binnacle, I'm sure thats what boats have) and gave the whole thing a ****** good pull, in my car there are no speedo cables or pipes, just wires, I like wires, wires are good, wires are easy.

After unplugging the two connectors (nice mechanism) the cluster was out and kitchen table bound. The perspex front is clipped on, as is the back, it's just a matter of working your way around, it's one of those annoying jobs reminiscent of taking a bike tyre off with forks, by the time you are all the way around, it's reconnected itself at the beginning. Having picked up the two coloured pieces of plastic that give the warning lights all the pretty colours up off the floor (I bet you drop them as well) the circuit board is exposed.

The rogue LEDs are fed by a ribbon cable, above that is a piece of rubber (pink coloured on mine), I assumed this was a piece of elastomer zebra first of all, but in fact is just a piece of rubber that keeps pressure on the ribbon cable, so it makes good contact with the PCB. This rubber obviously gets degraded over time and with heat, so it loses it's bounce, if you've noticed some segments light up after a long journey, that'll probably be the rubber expanding and re-attemting pressure. Anyway, to my mind it's a rubbish connection (as witnessed by its failure rate).

If you liberate the board from the white plastic slighty by pushing the adjacent (below the connection) white clips to one side, you should have enough room to see a gap between the offending rubber and the ribbon cable, try and improve upon it by pushing the rubber up slightly, I used a precision scredriver. So, now you need some more pressure, I slipped in a strip of 2mm rubber (funnily enough this was an elastomer strip from an old project), I chose rubber so I didn't put any strain on the board and rupture any joints after assembly. The 2mm was a little large in all honesty, but I didn't fancy doing this again, I get bored easily and I figured the original rubber was only going to get worse. I repeated the same on the other LED ribbon connector.

Because the rubber was a little thick, the white plastic clips had a tendency to push open up again, so I pushed some tiny white plastic wedges in the opening to stop it from happening. this is really badly explained, but I reckon it will make sense when you see it live.

As all good manuals suggest, re-assembly is a direct reversal of the dis-assembly process ... although you won't be needing the coat hangers again, use them for torturing the Parts Manager at your local Stealership, when you next pop in to scoff at his new cluster prices.

So there you have it, in essence it's the integrity of the plastic ribbon cable to PCB connection, you might have a better idea for resolving it (can't see how, mine was brilliant), but it is that connection you need to sort out.

Cash, beer or new 16" alloys gratefully accepted.

 

[Myros]

just in case you are ham-fisted like me

there is some discussion here,

http://forums.mercedesclub.org.uk/showthread.php?t=10956&page=3&highlight=digidash

 

[Tim Green]

Thanks for your help. I will have a go, but it all sounds a bit "dodgy" and not at all what one expects from a £30K vehicle! As an electronics engineer myself, I am well aware that most problems are caused by mechanical items such as connections, and one would have thought the MB engineers would be aware as well. Amazing how easily reputations can be lost! TG

 

[television]

Thanks for your help. I will have a go, but it all sounds a bit "dodgy" and not at all what one expects from a £30K vehicle! As an electronics engineer myself, I am well aware that most problems are caused by mechanical items such as connections, and one would have thought the MB engineers would be aware as well. Amazing how easily reputations can be lost! TG

When you think of some of the super ribbon connectors that one can get these days, it does mak you think

 

[jberks]

Is there an established method for removing the binnacle to get access to the displays, Rgds TG

In a word -Yes
http://forums.mercedesclub.org.uk/showthread.php?t=25872

Most MB connectors are pretty good but this was outsourced to VDO who make a mess of dash displays for a number of manufacturers. A quick look at BBA-Reman or Speedofixers web site and there are issues with BMW and Audi dashes too.

 

[jaymanek]

well i use the rubber band trick very regularly and is a good and permanent fix...

 

[Tim Green]

Well I did the job, but like some other people - without 100% success. I found it quite difficult to remove the panel, but after that the information provided made life much easier - thanks. I used some insulation that I stripped off wire to make pressure pads - 2 or 3mm seemed about right. The displays both work now, but there are still two lines accross the clock/gear display which do not work - I guess the display itself must be faulty, very annoying. I will contact the suppliers mentioned to see whether they can help with an exchange or repair. Do any other cars have the same (identical) display?

 

[Tim Green]

Sorry - I meant the same instrument panel as the w210?

 

[michaelh]

Did this repair on my W208 CLK and found that, although there was a significant immediate improvement, the last of the pixels only came back over a 3-4 day period. May just be a case of waiting a day or two longer.

 

[jberks]

Moisture etc can affect it too. I doubt there is a permanent fix aside from a complete strip down and rebuild. I doubt the displays are defective , it will be just the cable connections. It clearly can be done as speedofixer guarantee their work but I imagine they strip it down further than we dare.

 

[Tim Green]

In view of jberks comments, I thought I'd have one more go, and this time it does all work - but for how long? I did two things a bit different - firstly with the pressure pad removed, I used a round metal skewer to apply pressure onto the ribbon cable where it is fixed to the PCB. Then, when the pressure pads were in place and the parts clipped together, I used 2 small self tappers to help hold the white clips fully interlocked in place and firm up the installation. I can't say I'm 100% sure of a permanant fix but here's hoping.