Is this a new problem or have you only just noticed it? I ask because when I put my 1990 De-dion car on the road a fellow motorist kindly informed me that I "had no f'in brake lights", which I replied to with a good shove on the pedal to show that, actually, I did have the requisite illumination... To investigate what was happening I wired a warning lamp from the brake switch and found that it was possible, especially in slow moving traffic, to stop the car using light application of the brakes without illuminating the brake lights. I gave up on the pressure switch at this point and engineered a mechanical switch operated from the brake pedal, set up so that the lights come on as the slack in the pushrod is being taken up. Oddly enough Caterham changed to a mechanical set up sometime in the 90's.... Brian.