Just as luck would have it when I started to investigate, the wipers worked fine, and I could not locate any problem with them. Whilst I was in the area of the fuse box though I thought I would continue to remove the redundant relays, I still had the heater, front fog light and another couple of relay that were no longer needed, so I started to remove these.
Whilst I have pulled out the relays, and any fuse that I thought would not be needed, I needed to check all the operations of the car (lights, wipers, starting it…) Just when I did this the only item not working was the wipers, this was lucky, so I started to trace the issue again, what I noticed was if I pushed down on the fuse the wipers would function, so I looked more carefully at the fuse that had been tested fine about 2 hours previously, when looking at it closely, there was a hairline crack in the fuse, this obviously was the issue, and explained fully why it was only happening some times.
I still continued to remove the redundant wiring from the car, and also started to remove some of the reinforcements from the bonnet and doors, this total weight was about 10kg, so thats a good reduction from my weight of 1207kg when I was at Croft. Just need to trim out about another 130kg’s or start to go on a diet, as the minimum weight for the class is 1050kg, and at least one other competitor is under the 1100kg mark.