light bulb with light either way. It doesn't know + from -
12v DC motor will spin backwards if hooked up backwards so would work. Multimeter is best way to test.
I was wondering where you were at when you posted. Now I understand.Doh. I remember using a small DC lamp for something in the past. It must have been continuity rather than polarity. I gave a few suggestions while watching the F1 and didn't really think about it.
Nice to see the panel all lit up and working though.
Was a tad concerned that the power supply might give too high a voltage at low loads but it seems to look ok.