Well after a 2 month break, I finally got my car fixed and back together today (original post).... I still don't know the route cause of the fault, but I do know that both the ECU and my Power Commander are toast - an expensive failure, as I don't have a backup of the map (unless PDQ keep copies of all of the they write). The obvious culprit is the reg/rectifier, but after extensive testing, it appears that the original, plus a replacement are both behaving in exactly the same way....

A huge thank you to all of those who helped - from moral support, to testing parts, to sending me parts in the post! A special thanks to Andy Bates, who is one of the kindest, most helpful people ever - thanks Andy.

Now I need to see how many more driving days I can get in before the tax is up at the end of next month!

Great news mate, glad you got it sorted in the end, I bet that first drive was a good one.