Speedometer - C180 or w202

[martinv]

Hi folks,

yet another problem - I hope they stop soon as I really love this car but now the speedo has stopped working. Does anyone have any clues on whether this is easily solved by a replacement part or is it a major job?

120,000kms on the clock.

Cheers & Thanks

martinv

 

[sixpack]

Speedo

Hi Martin,

Did you know about the sticky speedo problem on 202s?. Mine sometimes stays at 0 when moving off, then jumps to correct reading a few seconds later. If it stays at 0 longer, a quick thump on the side of the dash cures it! I read that its caused by the needle sticking to the stop pin on the dial & can be cured by cleaning the pin. I havn,t tried to repair it yet as I dont want to strip the dash.

Regards

Peter

 

[sedstevo]

How about this one... my speed and tacho (C200 '96) will occaisionally stop (i.e. return to 0) when I'm driving. This only happens for a split second, then they return to the correct speed/revs. Also, the lights along the bottom of the binnicle flash briefly. The illumination, temp gauge and fuel gauge remian unchanged. Anyone heard of this before...

 

[new2mercc180]

C180 speedo intermittent fault

Did thumping the dash work for Martin?
I have just got a C180 and the speedo was working fine for a few days, but now generally doesn't work. My local garage muttered something about a cable in the gearbox needing replacing, which sounds very expensive.

 

[jberks]

The speedos are electronic so fed from a sensor on the gearbox. I don't know mb ones but I did have a sensor on a ford changed once and that was a 5 min job. I can't imagine the MB one is any more complex.
The problems you describe sound more electronic than mechanical though. Check the contacts in the plugs at the back of the cluster.

 

[C220GJS]

The speedos on W202 C class models are electronic.
Haynes manual says,
"The signal for the speedometer is derived from the ABS wheel sensors,of which there are three on early models, and four on later models. The ABS control unit takes the average speed from the wheel sensors ,and this is fed to the speedometer. Therefore, in the event of a query on the operation of the speedometer, check the connections to all the wheel sensors, and to the ABS control unit ,as well as all the ABS wiring."
Hopefully just a bad connection, if it's intermittent that may be the case.