ABS light comes on with main beam

[tooheavy]

Hello, today we have discovered that the abs warning light comes on with main beam. Also the speedo dropped to zero and the gearbox seemed to change down. Car drives normally at any other time, including with dipped headlights on. Car is a 210 estate from 2003 (E220cdi).
Thanks in advance

 

[Ted]

I would be checking the earth for the instrument cluster. It will be a brown wire into a multiplug.
Do the dash lights work as expected?

 

[tooheavy]

I would be checking the earth for the instrument cluster. It will be a brown wire into a multiplug.
Do the dash lights work as expected?

Yes dash lights work normally. Whereabouts should I be looking for the earth?

 

[Ted]

Dash lights working normally suggest that the earth should be ok, though there could be a section of track that is broken.
Difficult to advise further. I would be using a test light to see if the main beam warning light has a decent return path to the multiplug, and from there (brown wire) to a good body connection.
A good auto electrician should be able to check this out without too much trouble or cost.

 

[tooheavy]

Thanks for your help. It was a bad earth near the driver's side headlight, a new earth connection has been made there and all symptoms have disappeared.