PeachParts Mercedes-Benz Forum - View Single Post - HOW-TO: W126 Odometer Repair, Clock Capacitor Replace

JamesDean · #9 01-02-2014, 09:46 AM

Quote:

Originally Posted by steh-fan

I can't believe it!
I was so happy that the clock is finally working accurately, but now I realized that my speedometer is about 10-15 mph too fast (depending on the speed).

Could this be in connection to the old capacitors? Or what else could it be?
I replaced the gears (but miles are correct as tested with GPS) and soldered the connections to get the speedo-/odometer off the board.

Thanks for your continued help!

If the miles are correct we can conclude the speed signal is correct and the problem lies in the circuit that controls the speedometer needle. I would start by replacing the caps. They might not be providing enough power to drive the little motor that runs the speedo needle. I'd also reflow all the solder joints on that board as well. There are not a huge amount so it should be fairly straight forward.