Community Forums

Gary RVRoamer · 04-09-2020, 10:18 AM

Quote:

I understand white and black wires for 12 V current.

Then you are probably mistaken because there is no widely-accepted 12v wiring color standard. Fleetwood (and now Rev Group) typically used white & black for general purpose 12v hot & grounds, so you are probably OK on your coach but don't try to apply it elsewhere, car, RV or boat. Even if common black, white & red are used at major connections like batteries, the wiring harnesses are often complex enough these days that a multitude of colors will be used to help distinguish circuits.

Let your VOM be your guide...

sibe · 04-09-2020, 10:34 AM

120V have code standards, , Dc has a few recommendations..

Auto industry had ZERO as the RV ... My winnie is green, neg, purple pos.. the wires do have numbers...

richard5933 · 04-09-2020, 11:14 AM

The only consistent standard I've found for vehicles is with regard to battery connections: red for positive and black for negative. I've never seen any other colors used for that. Everywhere else? All bets are off.

Alan_Hepburn · 04-09-2020, 12:14 PM

One problem with trying to standardize the 12VDC side is the sheer complexity of 12V systems. With 120VAC it's pretty simple with just hot, neutral, and ground. But take a look at a typical 12VDC wiring harness going through the firewall of any vehicle - the wires are all carrying 12VDC but with the myriad of different circuits being used it's almost impossible to use a standardized scheme. There's only so many colors available after all...

RKins · 04-09-2020, 01:20 PM

I was happy to see that on my Newmar, all wires are marked on the casing what they are used for. My owners manual has every wire color and gauge identified. It doesn't show schematics but was happy to see all the wires explained and marked.
Now once I leave the Newmar wiring and connect a 3rd party device, all bets are off.

n2zon · 04-09-2020, 01:35 PM

Three coaches, many wiring harnesses, no discernible standards within or across them. Major 12V systems (battery harness, starter, main ground) are consistently red and black, but that's about it. My voltmeters are my close friends. I do have some sympathy for the coach manufacturers. HWH no doubt has a standard. Dometic, too, and all the rest. Sometimes, their standards change, or are ignored to keep costs down, after the original harness was manufactured, so that repair and replacement parts aren't consistent with the parts they replace. Sometimes different generations of systems have different color codes because their designers were different and chose different colors. They cater to the coach manufacturers, who probably don't really care if they change at the Purchasing level (the level that matters).

Also, if checking for continuity, always check for voltage first. It saves on meter fuses, if you're lucky, and on new meters if you're not...

A32Deuce · 04-09-2020, 01:38 PM

I know a guy that rewires cars using the same color wire for everything because he got the spools of wire for free. Easy when its being done 1 circuit at a time. Go back and trouble shoot a problem, WOW. Ok to electronically trace a wire but physically a nightmare. Like I said before, pull the panel cover off and you can see the colors for each 12 volt circuit with its fuse. Write it down and you will know what you are working with.