Hello Dan,

1) About resistors, if you use either Faller 180667 or Viessman light masts, the resistor is included. It is either visible (resistor soldered to one wire) or invisible (probably SMC component inside the mast or socket).
However, beware if you purchase bulk LEDs. Always put a resistor, 1K is a mean value for most LEDs.

2) Now about the + and - for DC, there is a trick !
If you look at Viessman light masts equipped with LEDs, they have yellow and brown wire (with or without a visible resistor).
Now let's suppose you have a 16V Viessman AC transformer, complemented with a Viessman 5215 rectifier which provides 22V DC.
Go to this page https://viessmann-modell...nics/108/2a-power-module and click on FAQ tab, you'll see various examples of connections.
On these sample connections, you see brown light mast is on brown output of rectifier and yellow light mast is on red output of rectifier, so the conclusion would be, if you apply traditional color convention: OK Brown is ground (-) and red is +.

And here is the trick: Now download the 5215 manual, and goto page 2, section 3: Output RED is NEGATIVE and output BROWN is POSITIVE.

So in your case V+ is brown, and V- is yellow.

I've recently experienced this (I knew it, but has forgotten it): See https://www.marklin-user...frared-sensor#post646793

Have fun.
Fabrice

Yup, seems crazy, but color coding varies among manufacturers. Just test wiring. Same variation with digital decoder brands, but here testing may lead to fails.

I had a similar polarity issue with Schneider Swiss Type L signals. I wanted to use Marklin 60832's in the mode that allows 8 individual lighting output but the polarity of the power output is opposite what the signals require. This means I could only get four outputs. Not as economical.

Regards,
Roger