Jeez euno...... that's like building the national grid for me - I ain't no engineer.Bit far or I would have given you a hand. They don't have to work for MOT, although non working fogs may be picked up as an advisory. It's a simple wiring circuit to build. Just some wire rated at greater than 10A, a 10A fuse and holder, a 3A fuse and holder and a 30A relay (as well as the switch of your choosing, e.g. the fog stalk switch).