Evening all.
The sidelights and dash illumination stopped working on this car so it was brought to us and wouldn't you know it now they all work!

Pulling the tail lamp relay (engine bay fuse box position 6) creates the same fault described so obviously a fault in this area.
What i have found is that the ground side switch to the control side of the relay has 1.47 volts climbing to 1.60 when other loads are used.
Unfortunately we don't have access to a wiring diagram to check for volt drop at where the ground switch originates from so this is what i need if anyone has said diagram.
Thanks in advance

Luke

Also checked at the switch itself and it switches a NBV to 0.02 volts when side lamps are selected and there is no physical connection between this output and the relay supply wire, so i suspect its just a signal to a control module rather than a direct connection? I stand to be corrected!