I have a double axle trailer I bought cheap.

It has a black box...



And It has drums with 2 red wires...


The guy I bought it from has 2 sets of 2 conductor wire routed to the drums but it is not connected.


My truck has a trailer brake controller installed and I just need to finish connecting this stuff.

Any help would be great!

Tim

 

What is the black box? Does it have a battery for a trailer brake break-away switch? If so, is the battery good and does it also have a break-away cable and switch?

Wiring the brakes is pretty easy. One wire on each axle goes to ground, one ties to the other wire on the opposite axle and terminates at the break-away switch or the plug if no break-away is installed. (You probably should install a break-away if one is not installed to be legal)

 

Here is a pic of a 7-way plug diagram in case you need it.

 

electric brake use a power and ground to operate the magnets. so if you hook your ground to one wire and your power to the other wire both of these have to come off the actuator in the drum aka the round magnet you can see, they will work. from the looks of the one in the picture they look like they need replaceing.if they work they will click when power is applied. the box looks like a junction box mabe doesnt look like any type of break away box

 

Ok, thanks.

I was confused when I saw 2 red wires. Guess I was expecting one red and the trailer itself being ground. Should I run the grounds back to the plug so it's actually grounded to the truck?

I'll take a battery and tickle each (4) sets of brakes and see if they click.


Thanks again.

 

As these guys said, the magnets are basically wired in parallel. Some of the 2 conductor wire for trailer brakes has 2 layers of insulation, the inner of which is translucent and you could miss it if you didn't specifically look for it.

On the ground side, I'd run the negative side to the junction where everything from the trailer's cord hooks up, and hook them both to the ground wire from the trailer cord to the truck, and to the chassis.

Do hook up a break away switch and battery.

Both Dexter and Al-Ko have very nice downloadable pdf manuals for free.

Under "Service Information" select complete service manual.

http://www.dexteraxle.com/products___literature

And here, just click on "Owner's Manual".


http://www.al-kousa.com/

It is worth it to save both to your hard drive

 

Ok, Thanks!

I connected everything up and I'm getting about 4 volts in the blue brake wire with just a 2x4 on the pedal.

I tickled the brake drum wire with the 4 volts and all I'm getting is a hum.

Should I try 12 volts or does this mean they are junk?

 

If you apply a full 12v to the magnet through an amp meter, you should see about 3 amps, give or take .2 or so.

With an ohm meter, you should see around 4 ohms or so. There should be no continuity between either lead and the magnet's housing.

 

That 'black box' has or should have 7 terminal studs inside, it is made by NAPA. The studs will have a 'color' name wirtten on them. The colors are the same colors that are found in a 7-pin wiring cable. Connect the right color wire coming FROM the trailer to the designated terminal, then connect the right color wire coming from your 7-pin plug to the designated terminal, WALLAH your plug and trailer have the correct match for your factory plug.

If you want to get fancy or actually better stated want to protect your trucks wiring, you can insert a fuse in line with the wiring that goes to your trailer plug side so all your circuits are fused. That's the way I wired ALL of my trailers, used a fuse in-line with each wire and the color codes called for on the terminals. Most all trailers built in the last 10 years have been wired with the color code standards that are used in the diagram in the above post if they are commercially manufactured. You might want to make sure your trailer wiring conforms to the color code before you just hook everything up using the color wires you have coming into the box. You can look at how the colors match up on the terminals from both sides to see if it is wired standard.

Hope that helps.

CD