I'm not familiar with either of the specific units here, but a generalised tip that could come in handy for anyone wanting to check out a loco and its pick ups:
I have a transformer controller to hand with a couple of flexible cables/wires attached to it and the other ends bared. I take the unit to be checked and chock it upside down on a handy soft cushion and just probe around the wheels and chassis in a methodical manner to find out the current flow routing. If no transformer available, a battery can be used instead, using mini alligator clips to attach the wires to the battery or even makeshift things like paper clips or washing line pegs. Same method can be used for checking lighted coaches of course. Crude but effective! Its the sort of thing I sometimes used to do rather comfortably lying in bed instead of falling asleep watching some boring TV programme!
EDIT
Soldering to batteries can be dangerous
DON'T try unless you really know what you are doing!