Help identifying wires, please

[JRRNeiklot]

I have 3 white wires coming from the junction box under my camper. They transition into a black wire that ends in a ring terminal. I have no idea where this wire goes. I don't know if it's a ground or positive, if it's trailer brakes, or what. The previous owner has apparently engaged in some redneck engineering. I'm including a link to a picture, since I can't figure out how to post a pic. If anyone can help identify these wires, I'd greatly appreciate it.

Thanks.

https://imgur.com/3ZHLsBp

[DrewE]

Keep in mind that if the previous owner did any maintenance or repair on the wiring, then any wire color conventions that may have been there from the factory could well have gone out the window. Often one uses whatever color of wire is at hand and of a suitable gauge and type to do a repair, rather than driving to a store or ordering online and waithing for delivery of additional wire of a different color. To figure out what the wire is for, it's pretty much essential to figure out where it's going and what it's connecting to.

[cavie]

JRRNeiklot wrote:
I have 3 white wires coming from the junction box under my camper. They transition into a black wire that ends in a ring terminal. I have no idea where this wire goes. I don't know if it's a ground or positive, if it's trailer brakes, or what. The previous owner has apparently engaged in some redneck engineering. I'm including a link to a picture, since I can't figure out how to post a pic. If anyone can help identify these wires, I'd greatly appreciate it.

Thanks.

https://imgur.com/3ZHLsBp

Try to rephrase your description. You say 3 white wires coming from a J box. What is coming in and out of this j box? What are they hooked to in this J box? Are all three and the black wire hooked to a ring terminal? Where is this ring terminal? If black and white, black is positive. If black and red, Red is positive. Are we talking 120 volts or 12 volts. Is this romex wiring or single strand wire? Not enought info.

[wa8yxm]

Most RVs the techs who build 'em were taught to wire by House standards where White is neutral. so they wire white to negative.
If you have white wires comign into the box and a big black with ring terminal

ODDS ARE.. and I tress ODDS cause there are no guarantees.. Ground.

Your meter is your friend... Clip the black lead of a volt meter to the ring terminal and find the companion positive wire Then plug in (making sure the terminal touches NOTHIHG other than the meter lead, or rather nothing conductive) and see what it says. 13.6 Excellent. but if it says -xx.x somethign is bass ackwards

ohm testing is good too IF you know how to do it But on many RVs the positive wire will show near zero ohms to ground.

[Acampingwewillg]

You could ohm test each wire to ground? I know sometimes this is hard to do but it's a thought.

[JRRNeiklot]

So it just needs to find a battery negative?

[Joe417]

I took a look but your picture was too blurry to get anything from it.

In general, I've found white wire, in all the campers I've owned, to be ground or the return and other colors to be positive, but there's no guarantee. Especially if someone has been "fixing things".

I took a look at the schematic for my camper and all low current 12V circuits returns were white with the exception of the jack motor return wires and starter return for the generator. From the jack motors to the controller, the returns are black but from the jack controller back to system power the return is white. The return for the generator starter is Black, but that is a 2 AWG high current circuit.

It could also be 120 volt AC wiring.

[fj12ryder]

I think you better go back and get some better pictures. That picture is pretty worthless.

Link