[retailer]

I think these little beggars were the cause of the issues I was having - with the meter out and a 3k3 resistor in it's place I could measure approx 10mV across the resistor(ie meter) on all of the insulation test switch settings, in the final test mode set to either A1 or A2 I could measure anything from 100mV up to 1V across the resistor depending on the anode current switch setting. I wasn't sure at what point in the test procedure the capacitors were in circuit but thought that I'm going to replace them anyway it might as well be now. With the capacitors replaced a quick check with a DMM across the 3k3 resistor and I now measure zero volts on all of the insulation test switch settings, I'm 90% confident the current issue is fixed, I'll keep my fingers crossed there are no others apart from calibrating.