It has been over a year since we got the camper out and I don't remember which wires go to positive and negative. I've got one battery and one red wire and two white wires. I know color doesn't mean much but I thought that I would mention it. The red wire is thicker than the other two. I vaguely thought I remembered the red to positive and the other two to negative. But, when I hook it up like this the lights are dim and do not charge when I plugged into 110. Everything works except the lights and furnace. My converter is only a couple years old. Since I wasn't very sure about the wire connections, I'm thinking it had to be that I don't have them on correctly. I've tried followiing the wires but it is very difficult as they seem to disappear under the floor. Like a car, would the negative actually go the frame?Is there a way to figure this out using a multimeter?Thanks in advance for any help!

RED goes to positive. On RV's Red and Black are positive. WHITE is negative on RV's. If you disconnect the battery, and plugged in and the lights are not bright, then either the Converter is bad or its fuse is blown which will happen if you made a mistake on the battery cable hook up. Doug

1. turn everything off2. hook up battery3. turn on any fan4. IF it spins correctly ELSE reverse wires ENDIF DONE

Follow cable to frame ....ground

Methinks it would to good to ask...Are all wires the same size (gauge)?Find a lamp or something you can attach a loooooooooooong jumper wire toCHASSIS NEGATIVERun that wire out to next-to the 3 wires in question.Check and make sure your meter is set on the lowest resistance measuring scale.The Diode/Continuity scale is a guarantee of lowest reading ohms so select it.Touch one meter probe to a wire, the other meter probe to your jury-rigged chassis negative coming from inside the rig.Change from camper wire to camper wire. Do all three.Beware of the floating decimal point when you come back and report what you see.(example)RED "X ohms"WHITE WIRE # 1 "X ohms"WHITE WIRE # 2 "X ohms"

Red is usually positive and black is usually negative in a DC system. White is not a DC color. You will have to do as has been suggested and trace the whites back to see where they go. Since there are white wires I would also trace the red back as there is no guarantee that the red is positive either.

Which wire to positive on battery | Good Sam Community

42 Replies

MEXICOWANDERER
Explorer
Mar 28, 2016
I listed something unrelated to finding which witch is which. Slipped in a note about wire color coding done safely. I do not trust my own memory working on circus wagon OEM RV circuits. That's what a cell phone camera is for. But the confusion over black for chassis negative versus line voltage and white for chassis negative or AC neutral is entirely stupid. Color coding correctly is the way to go. I used more than 17-MILES of wire on the Kelley II. It has electric steering and 5-remote control stations. Sadly I could not repeat that work again today if my life depended on it. 1981 and there was pure amazement over my using LED and Sonalerts rather than pilot lamps and bells.
red31
Explorer
Mar 27, 2016
MEXICOWANDERER wrote:
He certainly did not READ the thread - I'm done.

you jest?
MEXICOWANDERER
Explorer
Mar 27, 2016
I like the marine YBC coding...

Red battery pos

Yellow battery neg

Black 120vac line 1
White 120vac neutral
Blue 120 vac line 2
Green earth ground

Chinee color coding is a riot. 120vac

Brown
Brue
White with gleen stlipe
Maybe

Chinese house wiring code: 600 volts 24-gauge wire.

I read stats -somewhere- that claimed there was 10,000+ electrocutions/year. They are convinced ground wires are an utter waste.
allkidd
Explorer
Mar 27, 2016
dougrainer wrote:
westend wrote:
allkidd wrote:
Okay, traced the white wires and they are both ground. I don't understand why two grounds going to the same place?
What are the sizes of the wires?

Because they were to lazy to run 1 large gauge. It is common on some RV's to have 2 small gauge wires on either the Positive or ground instead of 1 large gauge. Doug

That is exactly what they did. The negative wires are about half the width of the positive.

Thanks everybody for the great responses! Problem solved! Couldn't have done it without the help.
dougrainer
Nomad
Mar 26, 2016
westend wrote:
allkidd wrote:
Okay, traced the white wires and they are both ground. I don't understand why two grounds going to the same place?
What are the sizes of the wires?

Because they were to lazy to run 1 large gauge. It is common on some RV's to have 2 small gauge wires on either the Positive or ground instead of 1 large gauge. Doug
westend
Explorer
Mar 26, 2016
allkidd wrote:
Okay, traced the white wires and they are both ground. I don't understand why two grounds going to the same place?
What are the sizes of the wires?
allkidd
Explorer
Mar 26, 2016
Okay, traced the white wires and they are both ground. I don't understand why two grounds going to the same place?
dougrainer
Nomad
Mar 26, 2016
Bob Landry wrote:
Four pages of responses to verify that red is positive and white is ground in trailer wiring. I knew there was a reason why I love the Internet.

Just proves that MOST have no idea what they are talking about. Doug
Bob_Landry
Explorer
Mar 26, 2016
Four pages of responses to verify that red is positive and white is ground in trailer wiring. I knew there was a reason why I love the Internet.
RJsfishin
Explorer
Mar 25, 2016
wvabeer wrote:
Follow each wire, the one that is fastened to the chassis is the negative.

I agree,....like the negatives are all bolted to the frame in plain sight right there where you can see it.:R