750 Breva Dashboard problem

750 Breva dashboard lights and clocks.
Mine go out and then come back on.
As do the indicators.
The mainbeam warning light works all the time (probably earthed at the headlight).
Therefore I suspect the earth lead flying from the dashboard multi connector.
Does anyone know where this is bolted to the frame or whatever?

Wiring diagram shows pin 25 on the dash connector as the earth but does not show the ground point.

The connector often get corroded, I’d disconnect the dash and check the plug and socket for corrosion