So I got my grandpa's old Simpson 270 Series 3 over the weekend. I've tested the DC and a small AC range and it is right on - who knows how many years this has been sitting or the last time someone calibrated it!
I can't get the needle to move for resistance however. I put in new batteries (4xAA and 1xD) and when I switch to the resistance ranges I can read the 1.65V of the D on the leads using another multimeter, but the 4xAA is measuring 8V! When I measure it at the battery terminals it is 6.5V so I don't know where the - wait - does it have the D also in series for this measurement? Yep, I see that it in the schematic. Any idea why the needle won't move when I short the leads? What should I check first?