A very hot and slow start to the week, continuing to work on the electrics.  I mounted the isolator switch on its bracket and bolted it to the bottom rail, although I am a bit unhappy with it there as it is stressing the rail slightly under the tension from the cable, but once the cable was clamped to the floor above, it seemed ok.  The cable needs further fastening nearer the battery box, but working under the bus was making me dizzy so I checked out the regulator and found one of the contacts furred up and high resistance, so I cleaned it with P600 and a touch of WD40.  I’ve ordered some contact cleaner to finish the job, when it arrives, but all three contact sets have been cleaned with P320 and P600 and are working now.  Frequent use will probably help.  Next job was to prepare the wiring for  and install the voltmeter, which was awkward as the body of the voltmeter was not insulated from internal bulb power, which I achieved by wrapping the bulb holder in heatshrink.  The whole installation took far longer than I felt it should have, including having to make an alternative fixing bracket for the meter itself, due to lack of room for the one that it came with.    Some rearrangement of the battery cables became apparent when I tried to clip the battery crossover cable to the floor, so some time was spent under the bus, my vertigo making this difficult, so I completed assembly of the control box whilst I recovered from that.  The battery cables still need some work though.  Final job of the week was to temporarily fit the cable cover behind the O/S front wheelarch, so I could drill the fixing holes in it and the bulkhead.  The latter are marked but not yet drilled, first job for next week.