Issue developed or presented itself with a power circuit after welding on the car. I did the usual removal of earths etc, however upon reconnecting everything found the instrument cluster for the aux gauges were powerless. Started the hunt, start looking for the most complicated combination of events within the history of the world then work backwards - chant of the engineer - and well it turned out to be one of the auto trip /reset devices - 50 amp unit feeding the distribution block. The unit had decided to crap out in sync with the unrelated activity of the welding. Have probably used these a dozen times across different amperage ratings, first to die. Just another thing to review and potentially chuck a spare in for. Swapped it out for a different unit and good to go. I like these for the ability to be able to isolate a bank of stuff with a push of a button, however suspect there are quality limits on the sensing and cycling also.