No worries! Glad you have got a bit deeper into the investigation. I wasn't that much help, just doing a bit of brainstorming. Hopefully the collective of BC will get to the bottom of it! The brake lights are 21W x 2 = 42W Using P=IV I=P/V I = 42/12 = 3.5Amps (if my o-level physiscs is serving me correctly!) So, something is drawing too much current on the brake light circuit, something down stream of the fuse and the switch shorting to earth? Or shorting to the reversing light circuit? Do the brake lights come on or is there just a current draw? Also do the reversing lights come on? If there's a short circuit, normally the bulb would not light or only light dimly as the current prefers to drain to the path of least resistance. Have you checked the earths? (trace back the harness from the tail lights, or someone on here tell you where it earths to frame. I've never had any problem in this area on my 7 but maybe others have? I seem to remember reading various threads about tracing short circuits. Peter