Speed wire
 

I installed a navigation system in my E280 1994 W124. Two calls to the mercedes garages around here still havent given me the correct information im looking for.
I am looking for a cable that runs to the speedometer and delivers a 12v "speed pulse". I have been adviced on a yellow/green at the cluster and, no that was not it. I have also been adviced that there should be acable down where the radiocables black/grey NO signal there.
Can anyone out there pls help me with the correct cable preferable at the radio cable cluster.

Sorry but I can't help you. Are you sure ther should be such a wire in a w124?

Anyway...you should pay www.benzsport.com a visit. There are some nasty modders on that board. And some of them have done navigation units to several cars...

There should be a green wire going to the back of your Becker radio in one of the harness plugs. I'm not sure if it's green on a W124, but it is on a W126.

Good luck.