Internal 12 volt Wiring Colors

[Booker B.]

Hi,

I could not find a topic on this specific question. In Automative and Marine 12v systems the 2 wire system consists of Red being Postive and Black being Negative. I have (belatedly) discovered that on our Trillium ( and other trailers from what I gather ) they use the 110 system of Black being Positive and White being Negative. I can live with that though it's a pain since a lot of 12v hardware is prewired Red/Black.

I am planning to put in a 12v power point. I just had a new convertor installed by an RV shop. I was interested to note that each 12v circuit (there are 4x15 amp on this model) has a different color Postive wire (red/green/yellow/blue). They have then tied in the black wire from each existing circuit to these lines. I did some searching on the web and I have found references to RV companies running different colored Postivies for each circuit throughout the trailer as a way to track down individual circuits for testing/maintenance/replacement.

So since the one line I am working on is easily accessible I was 'considering' replacing the existing black/white 16g circuit with yellow/white 12g (EDIT: reading more seems like 14g is fine for branch circuits). These would also mean that I 'should' eventually replace all the internal 12v with this new color system.

Thoughts? Doubts? Questions? Answers?

[james kent]

There's no logical reason why you can't use the colour combination of your choice. It's your trailer after all. BUT, For future reference and for anyone else who has to do any work on your trailer keep a detailed scematic and a list of colour usages, and wire guages.

[Garth M]

Hi,

I could not find a topic on this specific question. In Automative and Marine 12v systems the 2 wire system consists of Red being Postive and Black being Negative. I have (belatedly) discovered that on our Trillium ( and other trailers from what I gather ) they use the 110 system of Black being Positive and White being Negative. I can live with that though it's a pain since a lot of 12v hardware is prewired Red/Black.

I hear what you are saying... I worked in the automotive field for many years and was very used to the red=pwr, blk=ground. When I started rewiring my 1300, the house-style color scheme took some getting used to (and a few zapped fuses). I kept it original, primarily because I had a couple of HUGE rolls of 14 ga. black and white at home at that time.

In my 5500, Trillium kept the same wiring colors. There are a great many more circuits, most glued behind the ensolite - won't be changed anytime soon if I can help it. I'll probably not change much (still have lots left on those HUGE rolls too).

As the previous poster said, you should be able to use whatever color scheme you want, just keep good records. Repair shops just LOVE trying to trace home-done wiring when there is no legend...

[Byron Kinnaman]

FYI.. Wire color for house wiring can be any color other than white for the hot side. White is reserved for the neutral side. Trailer wiring seems to have adopted the same wiring color scheme. White the negative side and any other color the positive side.

My preference is to never rely on wire color but use a DVM to determine polarity. On a used trailer or anything else you never know what some body has done with the wiring.

[Pete Dumbleton]

One thing that one can do when one has lots of wire in certain colors is to paint the ends of the wire in the color appropriate for the use. For example, one can run two black wires, positive battery and negative return, and paint the ends red and white (I prefer white as the return wire, a la Scamp factory wiring rather than black).

[Darwin Maring]

Our Scamp uses the different colors for the DC wiring with white as the negative (-) for all applications and different colors black, red, and so on for the different (+) connections and it is labeled on their schematic. This makes it extremely easy to trace and test.

House wiring: White is light and green is ground the world around and that translates to: You connect the white to the silver screw and the black to the darker (Brass) screw and the green to ground.

By code, house wiring must be identified by putting the appropriate tape on the ends. Black is phase 1; Red is the 2nd phase and so on.

You can purchase a set of colored electrical tape to accomplish this. White, Black, Red, Blue, Yellow, Green and they are on small rolls (Check Harbor Freight)

[Booker B.]

Thanks for all your feedback. I am leaning towards sticking with Black+ and White- and using colored electrical tape to mark the circuit color where the line exits and enters hidden areas. That way it keeps the trailer in original wiring shape while clearly indicating what circuit is what.

Part of my decision is the current high cost of wire - I was shocked at how much even 14g wire costs. I probably will only upgrade the circuit for the 12v power point at this point.

[Roy in TO]

I picked up a pack of those numbered stickers used to label wires from Home Depot for about $10. More than enough to label both the trailer and the house.