Sorry but I haven't had time to check your suggestions yet, getting amp meter and will also have to source a clamp!
Yes I had thought about checking by removing fuses but going at it from the opposite end, removing all and then replacing, yours sounds a better idea!
Regarding the 2nd question, I will have to suggest this to my garage as I do not have a scanner, having to rely on electronic devices is not something we used to have to do in the old days, just refer to the wiring diagram and work it out for yourself, I've tried to 'find' a wiring diagram for the Scudo, virtually non-existant!! They used to put them in the back of the handbooks along with a full set of spanners.....well, those were the days!!
Thanks for your suggestions, will let you know the outcome as soon as I've put them into practice.