Machine is on and checked the voltage on the purple wire for both of the big blue capacitors. Range went up around 0.09 and would drop to about 0.03 on both of them.

Have included a picture of my multimeter to show that it is on DC.

Cheers!
Adam.

Something wrong with the meter or your technique. 
You should definitely be able to measure 18v on at least one of those caps.