Break away wiring

[drsmart]

I'm re-wiring the hitch wiring box on the pin box. I've got everything working such as running lights and turn signals but I'm not sure about the break away switch wiring. When I search the internet, I see diagrams with a break away switch and a break away box that is somewhere in the trailer.

http://www.etrailer.com/Merchant2/gr...u49444_800.jpg

Is anyone familiar with
the wiring? Is there an additional relay box involved?

Thanks
Dave

[paulinbaja]

The breakaway box you are seeing in the diagram is the battery box for livestock or cargo type trailers. Your hot wire should be from the line that is hot from the truck to the trailer battery (+ terminal). The other wire should go to the break line--often blue. The whole idea is for the break-a-way switch to set the breaks if there is a disconnect of the trailer at the hitch. The drawing you have does not show a fuse, there should be one near the point the break-a-way switch connects to the HOT line.

Because you are asking, you may want to seek advise from someone more familiar with this wiring!

[drsmart]

Thanks Paulinbaja. That's the way I thought it would be wired. Battery black and brake power blue, bridged through the breakaway switch. Pull the switch plug, contacts close, full battery to brakes.

[Irlpguy]

That is not a particularly good drawing and like drsmart indicated is the configuration you would find on a horse trailer or utility trailer. If you consider the "breakaway box" in the drawing as your house battery/batteries it becomes more clear.

On my 3402RL there are two wires going to the breakaway switch, one is blue which goes to the brake circuit in the pin box, the other is orange and black which connects to the "only" hot wire you should have in the box, likely black. This wire is connected to the plug and when hooked up has power from the TV, it is also hooked to the "non" fused side of the circuit breaker for your house battery supply to the unit. If it is in the correct place the battery cut off switch in the convenience center will not affect it, so it is live even when the battery cutoff is in the off position, as it should be.

Unless you are hooked to the TV there should be only one hot wire in the junction box on the pin, that is the wire from the TV and house battery where you get the 12V for the breakaway.

My daughters horse trailer has a small 12V battery (similar to a alarm battery) separate from the house batteries that supplies the breakaway as is indicated in the drawing you refer to.

Hope this explanation is not too confusing, it really is very basic as the breakaway is supposed to have power to it at all times and should it ever happen then the house batteries supply the 12V to the brakes.