Which wire to positive on battery

[allkidd]

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!

[2oldman]

MEXICOWANDERER wrote:
Methinks it would to good to ask...

Are all wires the same size (gauge)?

No. The red wire is thicker.

[2oldman]

fitznj wrote:
Get a multimeter from WalMart (real cheap) and use to to test each wire - this will a sure way of knowing which wire is Pos and Neg.

How?

[Happy_Prospecto]

How's your RV Fire Insurance?

[Johno02]

My thoughts are that if you don't know, you might be better off to hire someone who does rather than try it yourself. A mistake here can have serious side effects.

[fitznj]

Get a multimeter from WalMart (real cheap) and use to to test each wire - this will a sure way of knowing which wire is Pos and Neg.

[old_guy]

you can plug in the TT to electric with the battery disconnected and test the wires to see which is positive vs negative with a meter.

[WyoTraveler]

So which guess do think will be best?:B

If it were mine this is what I would do. Make sure wires are all free and not touchng anything. Plug the RV plug into your PU. Measure the voltage on the wires to ground.. You will know which one is positive. Very simple and won't be a guess. JMHO

[Old-Biscuit]

Fulltimer50 wrote:
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.

Unlike automobiles wire color in RVs are not standardized

In RVs from mfg. have seen
Red and Black are used for POS
White and Green are used for NEG
Also seen Black used for NEG.

Most common combo.....RED/POS and White/NEG

BUT no standard......so always best to trace cables

[Fulltimer50]

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.

[MEXICOWANDERER]

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 to

CHASSIS NEGATIVE

Run 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"

[Old-Biscuit]

Follow cable to frame ....ground

[2oldman]

1. turn everything off
2. hook up battery
3. turn on any fan
4. IF it spins correctly
ELSE
reverse wires
ENDIF

DONE

[dougrainer]

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