Really dumb question...

Hi all,

Just like in the title - I'll likely be picking my trailer up later this month, and I want to confirm one thing before I do:

the green wire (ground) attaches to the negative battery terminal, right?

I yanked the battery out and brought it north to keep it charged (which I have not had to do - the thing's keeping a charge marvelously...) -- now, faced with dropping it back in, I want to make sure I don't fry the thing!

Thanks!
John

Heh - my wife just reminded me that I'm bringing an electrician along with me (my dad) for the drive -- however, I'd still feel strangely better (don't mind feeling dumb if I'm dumb and alive/safe) if you'd all confirm/deny my suspicions...

[Bill]

The black wire is attached to the positive battery post. In some trailers, there is a fuse spliced into the end of this black wire, and the fuse may have red wires - but that doesn't change anything.

The negative battery post has two wires on it. One is white. The other is usually bare, but could have green insulation.

Good question - don't feel bad for asking, that's what this group is for.

Bill

[Wavery]

Originally Posted by Bill

The black wire is attached to the positive battery post. In some trailers, there is a fuse spliced into the end of this black wire, and the fuse may have red wires - but that doesn't change anything.

The negative battery post has two wires on it. One is white. The other is usually bare, but could have green insulation.

Good question - don't feel bad for asking, that's what this group is for.

Bill

Or green corrossion....... .....never heard of green insulation on the ground wire.....

I ditto Bill- black is positive, white is ground. If there is a green, it's probably ground. If you have an ohm meter, you can see if the resistance to the body on the green wire is zero or very low ( a few ohms). Make sure you hit the body somewhere that's tied into the frame etc.

BTW, I instinctively reversed these two which blew out the main breaker in the inverter. TM uses an AC wiring color code standard at the battery. DC standards are usually black for negative/ground and red for positive. I guess I equated white more with red and since I was working on the DC side voila! I shorted it and blew the fuse. Since I can't count on being any smarter the following spring, I tagged the wires to make sure I didn't do it again ;-)

Phil

Radio Shack sells a four pack of colored plastic tape. It is handy for tagging wires in the TM once you determine their polarity. It is also great if you have any outside dining flys or screen houses. Assemble the supporting pole pieces then using colored tape put matching colors on the joining ends of the various poles. With 4 colors and one no tape, you can identify four different assys. It makes assembling them very quick and easy.

[Bill]

In AC wiring (such as household power, and AC power in the TM), the color standard is well defined. Black is hot, white is neutral, green is ground. Some applications (such as 3-way switches) require another wire, and this wire is red. I suspect that this standard is rigidly defined in the National Electric Code (NEC), which is the Bible for household wiring.

In low-voltage DC wiring, I seem to see two different standards in use. In one, black is positive and white is negative. In the other, red is positive and black is negative. No wonder it is confusing! In addition, in most applications, it is the negative side of the system that is grounded - but not always. Beyond that, if there is a ground conductor, it is usually bare - but I have seen green. And in some applications, such as my wife's Saab, negative or ground is blue.

As I said, don't feel bad for asking ...

Bill

[Wavery]

Originally Posted by Bill

In low-voltage DC wiring, I seem to see two different standards in use. In one, black is positive and white is negative. In the other, red is positive and black is negative. No wonder it is confusing! In addition, in most applications, it is the negative side of the system that is grounded - but not always. Beyond that, if there is a ground conductor, it is usually bare - but I have seen green. And in some applications, such as my wife's Saab, negative or ground is blue.

As I said, don't feel bad for asking ...

Bill

Where it often gets confusing for some is that most US made vehicles have black as ground (as you stated). Then when you get to the trailer, white "should" be ground but you may find that the 12V "House wiring" has white as ground but the "Trailer light wiring" could have black as ground (mostly older trailers).

BTW.....I wasn't kidding about the "green" corrosion. If the trailer has a bare wire for ground (which is common), it's made of copper. When copper corrodes, it's green. If you have a green wire at the trailer tongue, you might want to be sure that there hasn't been a mix-up somewhere. I suppose that it could be the ground wire from the 110V system in the trailer (not likely though).

Did TM ever use green as 12V ground???? I can't imagine that...

Thanks everyone for the replies! I like the label idea - that'll help me in my absentminded old age...