DEcosse
If it's no Scottish it's CRAP!
... Im not handy with a multimeter and wouldnt have a clue how to use one either , is there a fuse somewhere id be overlooking ? ...
See here for tip on using your meter to check Fuses.
Note there are two fuses that will affect the tail/license plate light - Fuses 8 & 10
There are couple of clues you can check without even measuring anything
Does Front Park light come on
a) In 'Park' position of key
b) In 'On' position of key (tip - pull Fuse 9 which will keep main headlight off and make front park easier to see)
If neither position works, check fuse 10
If works in 'Park' but not in 'On' check fuse 8
If works in both then problem with wiring at the rear lamp end.