Strange Passenger window fault

I have noticed a very strange fault with my newly acquired MGF (96).

The passenger window does not function when the headlights or sidelights are on... However the drivers side is fine and once the lights are switched off it functions as normal.

Im not sure if anyone has had any experience of this or any ideas.

Thanks in advance.

Sounds suspiciously like a bad earth. Not sure WHERE, but I would start by examining any earthing points traced back from the passenger-side window switch.

Thank you, I suspected this may have been the case.

Ateast it will keep me busy over the bank holiday.

Yes that would be earth headers LH and RH under bonnet - take a look at this thread where to find them: https://www.the-t-bar.com/forum/roverlike-s-guides/97850-mg-f-tf-earth-points-locations-guide

Thank you so much for that. I will check it out.