Hi Flanders,
now you know 2 people!....you and Petermack right....I went on a tour of 4 garages...bought a bulb in a place similar to halfords-they couldn't open the light thing to replace the bulb but sent me to to nearby garage..they replaced the bulb, sent me on my way- realised afterwards that light still wasnt working...left work early and off to another garage-no joy!- they sent me to another place that did car electrics..the guy wanted to book me in for next week-explained situation to him and he said he'd get somebody to take a look...guy fiddled round with the wires under the steering wheel and then told me the brake lights were fine again!..I said I know the brake lights are fine-this is the reverse light that isn't working....that's when I found out that just as PeterMack said-it is a fog light-I only have one reverse....ahhhh...thanks for all the advice though..should have paid more attention-had it in my head I defo had 2 lights- thought I would have noticed before if I'd had only one.......