Junction box for Trailer lights

[joindy]

I was having trouble with Rockwood Geo Pro trailer lights and found out should check the junction box. Located galvanized metal box on the frame close to batteries. I had seen online what should be in the box...but when I opened it found lots of wires stuffed in there. I was expecting just the brown, blue, yellow, red, green, white etc associated with trailer lights. Unlike the nice boxes you seen online, this was a mess. I had bought a new trailer light cord with junction box....should I just remove the trailer light wires from the old box...hook up to new and leave all the other wires in the old box.

[rockfordroo]

Not sure what you mean by "trailer light cord." Maybe you mean the umbilical cord you plug into the 7-pin plug on your tow vehicle? If so, you can keep or change out the junction box, but either way, you need a junction box to protect the connections.

See post #6 here:

http://www.forestriverforums.com/for...rd-179425.html

for a schematic of what you SHOULD see with respect to the wiring colors.

HOWEVER - be aware that the manufacturers are not very good at using the proper colors. I know on my Mini Lite that the colors used don't match the drawing shown in the link. Take pics and/or write down the colors you find BEFORE you disconnect anything.

[joindy]

Yes....I am am referring to the 7 plug cord which connects to tow vehicle. As indicated in the post, I only thought I would find the trailer light and brake wires inside.....but there are other wires in the box. I will try to get a picture of it and maybe someone will be able to identify what all the wires are for.

[Blackrock]

This is pretty much industry standard for trailer wiring. Unless of course it's a travel trailer.
https://www.etrailer.com/Accessories...%20and%20Parts

[Jeffjeeptj]

I wish my 2018 Surveyor had a box. This is underneath fully exposed to road debris and grime. The connections are up behind the “first” crossmember, actually more of a tongue closure panel. I will be adding a box like the one in the above post for lighting. The grounds and battery positive will be re-addressed when I add the battery monitor shunt, solar charger, and dual batteries. The circuit breakers are what is between the battery on the tongue and the power distribution at the back of the trailer. I really like the piece of copper acting as a buss between two CBs. The middle picture is where the TV to TT harness wires are individually joined

[rockfordroo]

Originally Posted by joindy

Yes....I am am referring to the 7 plug cord which connects to tow vehicle. As indicated in the post, I only thought I would find the trailer light and brake wires inside.....but there are other wires in the box. I will try to get a picture of it and maybe someone will be able to identify what all the wires are for.

Look at Post #6 in the thread link I provided you above in Post #2 of this thread. The pic in Post #6 shows you what all the wires are for. It even shows the "box."

Just don't trust the colors unless you've verified them.

[joindy]

Here is a picture of the Junction box on my trailer. It is stuffed full of wires. Nothing labeled.

[rockfordroo]

There is no easy method here - you have to figure them out yourself. You will need a multi-meter. Start with the umbilical cord that's currently attached, checking one wire at a time. Either draw out the wiring or confirm it matches the Post #6 drawing as you go.

If you don't know how to do this, you will need to find someone familiar with wringing out wiring.

[Larry-NC]

Originally Posted by Blackrock

This is pretty much industry standard for trailer wiring. Unless of course it's a travel trailer.
https://www.etrailer.com/Accessories...%20and%20Parts

Yes! The umbilicals are manufactured by a third party, and you should be able to trust those colors.

When you begin to hook up a replacement umbilical, you can cut the splices on the old one, leaving a stub of the old umbilical at each splice. Then loosen the strain-relief clamp and remove the old cord and insert the new one. Now, one splice at a time, remove the old umbilical stub and connect the new wire of the same color. No confusion this way.

Larry

[babock]

Originally Posted by Blackrock

This is pretty much industry standard for trailer wiring. Unless of course it's a travel trailer.
https://www.etrailer.com/Accessories...%20and%20Parts

I use one of these whenever I do rewiring on a trailer. Currently, 2 out of 4 of my trailers have one of these and the others will eventually.

And NO wire nuts! All connections in the box are using quality crimp heat adhesive connectors(no solder) and a quality crimp tool.

[Flybob]

There are probably more circuits in there than just the lights. I would reconnect everything.

[D W]

Originally Posted by joindy

Here is a picture of the Junction box on my trailer. It is stuffed full of wires. Nothing labeled.

Don't forget you will have a wire for the brake-away control tied in there. You will also have a wire coming from the batterie(s) through the 30A breaker tied in there to your 7 pin cable and going on to your converter. If equipped, there may be a solar panel ground wire that will tie in there and generally there will be a battery disconnect switch wire coming from your 30A ATO fuse that passes through.

[babock]

Originally Posted by D W

If equipped, there may be a solar panel ground wire that will tie in there

If someone actually put a solar ground wire in there, rip everything out and start over again. In fact, if I saw that mess, I would start over again no matter what.