200TDi Disco Indicator Gremlin

[Chassis 33]

Has anyone experienced this before...? Using the original flasher relay indicators all work fine, but the green dash light doesn't, however the trailer dash light does. Swap to replacement relay and the dash light works correctly but the trailer light is permanently on, dimming when the dash light comes on.
How do these electronic relays work the green dash lights is it based on load sensing? eg 94w = no towing, 136w = towing? If so it sounds like a bit of a dodgy earth somewhere? Any thoughts?

Thanks in advance.
Regards
Iain