DC 12v Black and White Wire (12v Wiring Color Coding Guide)
The #1 rule when it comes to RV wiring is that there are no rules. What that means is that there are no real standards for colors when it comes to making RVs. This can be frustrating when you are upgrading a feature and the wire colors do not match up
The standard colors for 12 volt electrical systems are red is positive and black is negative. Sometimes RV makers change that standard and use the colors black and white with white being negative or ground. You never know what you will get when you open up an RV’s wiring system.
To find out more about this topic, just continue to read our article. it has the information you need to know about so you are not surprised or confused when upgrading electrical features in your RV. Take a few moments to see how this important information helps you and your wiring project.
12 Volt DC Wire Color Code
This will depend on the country or continent you are living in. The reason we bring the different codes to your attention is that while RVs are made in America and possibly Canada, not all products for RVs follow the American color code system
Then even the color code for America depends on the electrical wire system placed in RVs and products. For example, look at the table immediately below:
| Function | Label | Color |
| Protective ground | PG | bare, green, green-yellow |
| 2 wire ungrounded DC power system | ||
| Positive | L+ | usually red but no recommendation |
| Negative | L- | usually black but no recommendation |
| 2-wire Grounded DC power system | ||
| Positive (negative ground) | L+ | Red |
| Negative (negative ground) | N | White |
| Positive (positive ground) | N | White |
| Negative (positive ground) | L- | Black |
| 3-wire grounded DC power system | ||
| Positive | L+ | Red |
| Mid-wire (center tap) | N | White |
| Negative | L- | Black |
**data taken from https://www.allaboutcircuits.com/textbook/reference/chpt-2/wiring-color-codes/
As you can see there can be some confusion when you go to the wire in different products for your RV. The link under the table will also explain the color codes for Europe, Asia, Canada, and so on. While Canada has the same basic DC power system, the colors are often different from the American style.
What Does a 12v Black And White Wire Mean?
According to the NEC, the black wire is supposed to be the hot or positive wire. The white is supposed to be the negative wire. The green wire is supposed to be the ground wire.
This is the code that the NEC expects all American manufacturers to comply with. Then any wire with a marking, dotted line, etc., is supposed to be a positive wire. A black and white-colored wire is supposed to be a positive wire.
Only those wires with no markings are used for negative or ground. The markings are for your reference only and the markings and colors. They provide guidance so you have a consistent wire set up as long as you connect both ends to the correct terminals. If you don’t you could get a shocking surprise.
Also, you should follow the manufacturer’s instructions. If they say to use a particular wire and color at a specific terminal, then follow their instructions. What this means is that at one point a white wire can be both positive and negative.
What is a White Wire in 12V?
Generally and in theory, the white wire is supposed to be for the negative terminals. The reality is that you could possibly use any color wire for that function. RV makers have taken that freedom to new heights and often you do not see the color you expect connecting the negative terminals.
This can be confusing as there are codes they should be following but RV makers seem to make up their own codes as they go along. For example wires with stripes and dashes are supposed to be positive and wires with solid colors are supposed to be negative.
But when you look at your car’s DC system you will see that both colors of wires are solid. That has been the way it has been for over 100 years. There are products that will use solid colored wires for both sides of the electrical system. that is what everyone expects until they buy an RV or a product made in a different country.
In reality, you can use any color wire wherever you want as long as you hook both sides up to the same circuit. In other words, if you are using green as the negative it needs to be hooked to both negative connections. One end cannot be positive and one cannot be hooked to the negative side.
Wires are wires but the color-coding helps you avoid trouble.
12v Red And Black Wires
If everyone followed the color codes for wiring the world would be a safer place and less confusing. For a DC electrical system red is supposed to be positive and black is supposed to be negative.
That definition helps you when you buy a spool of wire that has the red and black wires molded into one wire. By that we mean that they are separate wires it is just the insulation that is joined together.
All you have to do is separate the joined wires and connect them red to positive and black to negative. But what if you have a stereo that uses yellow wire? If it is a solid color, it should be a negative wire but you cannot always be sure of that fact because most manufacturers do not follow color codes.
RV makers may use brown or the fan they installed uses brown and you bought a new fan that uses red, black, or green. It can be confusing and sometimes you have to use a multimeter to figure out which wire goes where.
As we research this topic, we are finding out that manufacturers do not care what color they use. Most likely, they will go with a color that costs them less and use that instead.
RV 12-volt Wiring Colors
It is said that the RV electrical system is partly an off shoot of the house electrical system. That means that black is supposed to be positive and the white color is supposed to be negative or the ground wire.
However, that is the ideal. RV makers do not subscribe to the ideal and make up their own codes. For example, Forest River uses striped duplex wires with white as the negative and the striped wire as the positive. Those stripes can be any color Forest River wants to use.
But. RV makers may use another color in place of the white when wiring clearance lights, etc. There really is no rhyme or reason for the way RV makers install and use wires. Sometimes the only way to tell which wire is which is by getting your multimeter out and doing some checking.
The table above gives the correct color codes but the NEC does not seem to be an enforcement body so no punishments will be handed out if the RV maker chooses to ignore those codes.
Your guess will be as good as ours if the RV and products manufacturers choose to use a different system.
Is black And White Wire Positive or Negative?
Yes! isn’t that a frustrating answer? You would think that the word Yes would not be answering this question and is meant only to confuse you and have a laugh at your expense. But that conclusion would be wrong.
The term Yes is the correct answer to that question. Sometimes the black wire is positive and sometimes the white is positive. Plus sometimes the black wire is negative and sometimes the white wire is negative.
Sometimes the white is a neutral wire or the ground wire, while black may not be used at all. When it comes to RVs, it is a real guessing game. The best thing to do is create a nice wire diagram for your current RV and keep it in a safe place. that way you will have a reference in case you forget which wire is which.
You can also use tape or stick-on numbers to help you identify which wire does what. Just make sure to record what color tape or which number you use don which wire.
Some Final Words
You may not know it by the above content but there are color codes that are supposed to be followed. There are several reasons why those codes are ignored. If you are unsure about where those colored wires go and if they are hot or not, pull out your multimeter and begin testing.
That will be the safest way to do your wiring project. Or make a diagram so you do not have to do testing the next time.
