Short in general illumination circuit

[Mkoenigsheim]

Please help guys, I am at my wits end.

When I turn n the lights in my 2007 polo - the fuse for the general illuminations blows - according to the fuse it is rear number plate and illumination.
I will fail an MOT with no lit up speedometer..

I have done the following:

Tried with a cable short detector to find a short - no luck.
Disconnected the rear number plate lights (cut the cable at driver door sill)
Disconnected all devices i the general light circuit:
Door electrics in the pillars, all switches, heating unit, removed the instrument cluster, rear number plate lights, light switch (is a new one)

Fuse is still blowing.

Is there any device I have missed and dows anybody have any other ideas where I can look?