Brakes interfering with R/H indicator?

[GillyD]

My o/h tells me that when I brake at a junction and indicate right, I get lots of flashing lights but nothing useful to indicate where I'm going! (He was driving behind me). Can anyone indicate an obvious cause/solution (I'm thinking earthing issue). If I'm not braking, there's no problem - anyone got any ideas?

[GillyD]

Many thanks - I shall have a bit of a looksee.