Battery wiring ???'s

[dig4gold]

Installed a new battery and forgot what all the wires are. I'm betting red is hot and black is ground . . . but not sure about the small wires, one black one white coming out of the holes above battery compartment. I check continuity with multi tester, and am confident in all but that small white wire I have connected to positive. Any idea? Any glaring mistakes?

[wa8yxm]

On Cars and trucks normally red is positive black is negative unless someone had to replace a CABLE.

But on RV's. any thing goes. the RVs are wired by folks taught house wiring (Black is hot) so what the black wire is .. You guess is as good as mine.

Your voltmeter is your friend.

We just solved an electronics problem in another branch of these forums where the problem was ... The Red wire (RV side) was NEGATIVE... The man's voltmeter proved it.

I would not take chances. I'd meter it

Isolate all lines. Hook a meter black lead (With a clip lead) to a known good ground. then plug in. probe all wires for 12 volt(wel 13-14) that will be a Positive lead.

if it's a trailer hook up to the tow vehicle and do the same. That too will be a hot lead (Positive)

The rest you are on your own

[4x4van]

On my '04 Itasca, positive is yellow, negative is white.

[ajriding]

Your picture is way too big and annoying to many readers as it makes the page wider than the screen. To edit your pic size, click "edit" post. at the end of the html gibberish, put a space then "width=350" just to the left of the brackets that contain the letters img and a slash. I cannot use those symbols or the forum will reject my post as bad html...
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Black and white--black pos, white neg
Red and black-- red pos, black neg
Red and white--red pos , white neg
This is good knowledge to keep around. Write it down in several places and put one copy in your DC elcetrical area.
Sadly, most wires will not be paired up like this.
RV manufacturers can get quite creative with their wiring colors. The trailer brake/reverse/running lights will not even match the vehicle side colors. That is something not fun to learn the hard way...

All that I have seen do use white as the RV ground color, but this means nothing on a forum.
Because a car is almost always and only black for ground this should have been the pattern to follow, but obviously early RV manufacturers did not work on cars, ever.

Your best option is to get a multi-meter so you can test voltage. Ground one lead to the frame, anything metal that is likely grounded, and the other lead to what you think is a positive 12 volts . you cannot get it to work through paint, the contact will need to be scratched down to metal, or find a screw head for ground.
If you get it backwards the voltage will show a negative, -12.

If you think white is the ground wire then use that for the negative test lead, and touch all other wires to see if you get a 12 volt reading.

Poor wiring, poor conductivity might give lower voltage, like 8 volts, or 2. This means battery is dead, or that the wiring or ground or something along the way is not conducting the electricity very well at all. This means the wiring is wired right and all looks good, but the wire or something is bad making it not work.
Old trailer will get a lot of corrosion on contacts or where one wire is attached to another or to a block and that corrosion will inhibit the flow of power...

[MEXICOWANDERER]

The most intelligent system is used on yachts.

Yellow is used for DC negative.

Black and blue for L1 and L2

[lane_hog]

Yeah, standards are only as good as whoever builds your coach. The 12V system in my Winnebago uses yellow for positive.

[2oldman]

Ron3rd wrote:
I'd never remember either. That's why I shoot a couple pictures with my phone before taking things apart. Problem solved

I've replaced golf cart batteries so I know the importance of that...especially when replacing 6 with 3.

I make a drawing too.

[MrWizard]

On the small black and white pair
Most likely
Black is Positive and white is Negative

It's a carry over from the first days of trailer building when the only wiring was 120vac inside
And running lights on the out side
New RV lights still come with black and white wires, not red and black, even though they are 12vdc lights

[Ron3rd]

2oldman wrote:
It's amazing what you think you can remember, but cannot.

I'd never remember either. That's why I shoot a couple pictures with my phone before taking things apart. Problem solved

[enblethen]

Actually it is the negative lead of a battery system and not ground. It should be red and black for DC systems.

[BFL13]

Bobbo wrote:

enblethen wrote:
I would suggest marking the ground wires with black tape and the positive wires with red tape.

I prefer green tape for ground. Black can be positive or negative under different systems/circumstances. Green is ALWAYS ground.

Green is ground with 120v, but could be positive with DC 12v. Eg 7-pin wire, and ISTR it was positive to the battery in somebody's RV a while back too. Can't remember the trailer's brand.

Not sure "ground" is correct with DC either, but we use it with our negative grounded RVs.

[Bobbo]

enblethen wrote:
I would suggest marking the ground wires with black tape and the positive wires with red tape.

I prefer green tape for ground. Black can be positive or negative under different systems/circumstances. Green is ALWAYS ground.

[Lwiddis]

“CLUCK”

[MEXICOWANDERER]

"CLICK"

[Lwiddis]

Cell phones with cameras...I dont touch nuttin until I take a picture.