Battery reconnect question

[akraus]

Last year when I disconnected the battery I forgot to make note of which one is positive and which one is negative. How do I know which group of wires to connect to the positive on the battery? I have 2 groups of 3 wires. One group has 2 white wires and a blue one, the other group has a red, black and yellow wire.   We just have a basic older Scamper.  It has a furnace, fridge and lights.  No ac or trailer brakes.

Thanks for the help

[AustinBoston]

Last year when I disconnected the battery I forgot to make note of which one is positive and which one is negative. How do I know which group of wires to connect to the positive on the battery? I have 2 groups of 3 wires. One group has 2 white wires and a blue one, the other group has a red, black and yellow wire.   We just have a basic older Scamper.  It has a furnace, fridge and lights.  No ac or trailer brakes.

Thanks for the help

There are standards, but if you have a blue wire but no brakes, then somebody has been doing their own creative wiring.  One thing always works: Follow the thickest black wire, and if it ends up connecting to the trailer frame, then that bundle connects to the negative (-) terminal.

Austin

[wavery]

It sounds to me like you are looking at the wires for the towing harness or something else.

The battery should have one white wire (Neg) that runs right down to the frame and one black wire (Pos) that runs to your converter (if you have one).

The blue wire is normally for electric brakes. Like AB says, someone may have wired the trailer not caring what color wires that he used. Although it is not uncommon for a trailer to be wired for brakes even though it doesn't have them.

[akraus]

I just went out to check the trailer and try to follow some of the wires.  The previous owner added a tape deck and it looks like to me that the red and blue wires are for the tape deck.  The red wire goes to the deck and I haven't been able to trace the blue one yet, perhaps it is grounded to the trailer somewhere?

I do have a converter.

[wavery]

I just went out to check the trailer and try to follow some of the wires.  The previous owner added a tape deck and it looks like to me that the red and blue wires are for the tape deck.  The red wire goes to the deck and I haven't been able to trace the blue one yet, perhaps it is grounded to the trailer somewhere?

I do have a converter.

Trailer owners often grab any wire that is handy when wiring stuff like that. They don't stop to consider that someone else may have to try to makes heads or tails out of it someday. :p

You should find a white wire (or possibly a solid copper wire with no insulation) coming from the converter and attaching to the trailer frame somewhere. Wherever that attaches, you should find another white wire that goes to the battery neg post. Also coming out of the back of the inverter, you should find a black wire (maybe more than one). What I would do is take a volt meter or test light, put the ground lead on the ground coming from the converter and put the hot lead on the black wire to see if you get 12V. If you get 12V, that's the hot wire going back to the battery.

Be careful not to hit a 110v wire. You may want to set your multimeter for 110AC first before you set it for 12v DC (just to be sure).