12V Socket Polarity

[Topflight]

You may want to check the polarity of the 12V sockets in your light fixtures.
I found one of the sockets had the black and white wires soldered on the wrong terminals.  You would never know (nor care) if you only plugged in an external light to hang over your bunk.  However, I plugged in a fan/light unit and found that the fan ran backwards.  The other two fixtures were wired correctly.
If I had plugged in a radio or some other electronic device, it could have caused damage to the device.