Hooking up brake wiring

[Capebuild]

I'm hooking up the brake wiring for the Dexter axle. There's two wires that come from each hub which activate the brakes. They are not
specific as far as polarity.... so either wire could be ground. Additionally, I've got the junction box installed and have a ground connection completed to the chassis
frame (see photo, 12 gauge white wire).

So my question is..... as far as hooking up the ground connection from each hub for the brakes, can I use a self tapping screw and screw each ground from each hub directly to the frame......
or do I need to run the ground wire from each hub all the way back to the junction box to connect with the white wire ground in the junction box.

I think just connecting each hub ground wire to the frame should suffice, but please let me know if that is not correct, and I should run each ground wire back to the junction box ground terminal.

Thanks.

John

[tony.latham]

I think just connecting each hub ground wire to the frame should suffice...

I think so too. (When I do this, the threaded screw gets a dab of dielectric grease) But... you could end up with one brake not working because of a bad ground. And I'm not sure how you'd know it.



Tony

[Tom&Shelly]

I think just connecting each hub ground wire to the frame should suffice...

I think so too. (When I do this, the threaded screw gets a dab of dielectric grease) But... you could end up with one brake not working because of a bad ground. And I'm not sure how you'd know it.



Tony

We learned our brakes buzz when applied. So part of our start-up procedure is to apply the brakes from the TV before starting the engine (so the noise doesn't drown out the buzzing) and listening for each side to buzz.

I used a wire ground return to the J box, but the above procedure should work either way.

One of my concerns with a chassis ground return would be that, if the wire from the J box to the chassis is flaky, or bad, there may still be a ground return through the ball to the TV. But that path is likely also to be flaky, so it might seem like you have good brakes (and lights--which we also check each time) when sitting still, but then the teardrop may have brakes sometimes and not others while driving--clearly a safety issue. Paranoid perhaps, but I have all wire ground returns for all three electrical systems in our teardrop, and only ground the chassis, for safety, to the AC power system.

Tom

[OP827]

I did run both brake wires to the junction box to TV hookup. My previous commercially built trailer (Boler) had both wires ran to junction box as well.

[Capebuild]

thank you for the replies and your thoughts.

I did a little investigation on Dexter's website and discovered they recommend each brake's ground NOT be wired individually to the chassis for ground.
Glad I found this. See attached.

[MickinOz]

thank you for the replies and your thoughts.

I did a little investigation on Dexter's website and discovered they recommend each brake's ground NOT be wired individually to the chassis for ground.
Glad I found this. See attached.

If one ground failed and the other did not - you'd have brakes one side, nothing the other.
That'd be entertaining.
Actually, here in Oz the design rules specifically prohibit using the chassis for ground. You are required to have a ground wire running through the plug, same as all the other wires.

[Capebuild]

I was going over the "how to" reference images I've been collecting and found where I had gotten the idea of wiring the brake grounds directly to the chassis.
It was from an image I captured from the Etrailer site. (Enlarge the attached photo by clicking on it.)
I guess maybe they need to rethink their instruction.

[twisted lines]

I guess maybe they need to rethink their instruction.

I Mounted my junction box yesterday in the same area you did, and noticed the labeling instructions inside
It would make a miserable job to follow the directions in mine, and wish I had all the colors to dab the post as you have

[Capebuild]

From what I gather it's not so much the colors as the functions that matter.
I just bought myself a tester. Once I get my brake controller installed on the TV I can see which blade on the 7 pin connector provides which function.
I'll match it all up that way once I get to wiring up the trailer.

[TimC]

I found it helpful (for my senior moments) to draw up a large upstream and downstream view of the seven pin pigtail. Wiring both the tow vehicle and the trailer brakes and nav light at the same time was easier with those hung nearby

[twisted lines]

From what I gather it's not so much the colors as the functions that matter.

My box list color / wrong location on 4 post’s ! Colors are good BS not so much
Standard’s Are good for easy repairs later.
Green or yellow would be a suprize on the brakes

[tony.latham]

From what I gather it's not so much the colors as the functions that matter.

Perhaps I mentioned this, but there are two different wirings (colors) for seven-pin connectors. The "Traditional" and "RV-Standard." It's kind of a what-the-hell kinda thing.

https://www.etrailer.com/faq-wiring.aspx

Scroll down to the pin diagram. I plug the trailer in before wiring the lights and check the trailer junction box with a continuity checker to see which one it is.

Tony

[twisted lines]

Thanks tony


seems that this is the confusing factor (7-Way RV Standard)
But the Coloring Diagram is the standard in Automotive since turn signals

[tony.latham]

But the coloring diagram is the standard in Automotive since turn signals

Unfortunately, they are not.



If you study my junction box closely, you'll note that I've got my brown chassi wires running to the trailer cord's green. And my yellow connecting to the factory's red.



Now... why they do two different color systems is... beyond goofy.

Tony

[troubleScottie]

If you want to use something like a LED stop light bar, you might need a 10 pin junction box. (harder to find but out there)

An LED bar needs a separate stop, left turn, and right turn wire, the additional 3 wires. The 4pin/7pin wire has stop/right turn and stop/left turn which is NOT the same. There are converters like CURT 56196 2-to-3-Wire Converter. They are small enough to fit into the junction box. This makes it easier to have a light bar on the trailer frame AND on the TD cabin/hatch/rear door.