Amen to that - thanks very much everyone, I will report progress.
I plan to fit the switch and and adjust it so that it opens as soon as I touch the brake. That doesn't seem to be how the previous one is fitted; I don't want the ECU to think I'm nervous on the brakes, so I might need to slacken it off if that happens. To balance this, I'll give the car a long blast at full throttle and hopefully teach the ECU that it needs to let me off the leash.
interesting that only Heinz and myself have (ever) had this problem. Hoping this is the cure!
