Breakaway Switch Confusion.

[Kelpike]

I recently purchased a 2003 25' Coachman travel trailer. The breakaway switch was crushed on the trailer so I replaced it but I am confused about the power for it. The old one only had 2 black wires coming out of it and going to a white and blue wire on the trailer. Those 2 go into the junction box in the trailer. The new one has 3 wires, blue, white, and black. First, what do I connect the black wire to? And second, it says make sure I disconnect the trailer plug before testing the breakaway. Does that mean it will draw power from my trailer battery?

[Edd505]

what came off it, 2 wire or 3? Most are two wire and makes no differance on which goes where it's an on off switch. Pin in it's off pin out it puts 12V to the trailer brakes.

[Kelpike]

Bobbo wrote:

Almost. Blue to trailer brake wire, whatever color it is.. Black to trailer battery positive (+) terminal. White to frame. Note that the LED light will light up anytime the trailer brakes are activated by the brake controller, not that you will ever see it.(Please reduce the width of your photo, like I did here.)

Hi, im not sure how to reduce the width of my picture. Thank you for clarifying my wiring connections.

[Kelpike]

Sorry Gdetrailer, I was creating my last post when you posted yours. Thank you for your reply.

[Bobbo]

Kelpike wrote:

Here is a picture of the wiring instructions. Is this saying blue from switch to blue in junction box? White from switch to white from junction box? And black from switch to positive on my trailer battery?

Almost. Blue to trailer brake wire, whatever color it is.. Black to trailer battery positive (+) terminal. White to frame. Note that the LED light will light up anytime the trailer brakes are activated by the brake controller, not that you will ever see it.(Please reduce the width of your photo, like I did here.)

[Kelpike]

Here is a picture of the wiring instructions. Is this saying blue from switch to blue in junction box? White from switch to white from junction box? And black from switch to positive on my trailer battery?

[dodge_guy]

That's good to know GD. But seems to be complicating the system! No reason to have an LED when you can see if the plunger is out.

[Gdetrailer]

Instead of arguing perhaps do an Internet search..

What are the functions of a three wire breakaway switch..

"What are the Functions of the 3 Wires on Hopkins LED Breakaway Switch, # HM20059

Question:

current brake away has only 2 wires, this one has three,black,blue,and white. will this still operate correctly? and how to wire into only 2 wires?

asked by: Terry

Expert Reply:

You are correct, the Hopkins LED Breakaway Switch, # HM20059, does have 3 wires. The white wire is the ground wire and should be attached to the trailer frame. The blue wire on the switch will connect to the electric brake wire coming from the trailer side connector. The black wire goes to the break away battery. This part is just a switch, if you need a new system, I recommend Engager Trailer BreakAway Kit with Charger and Tester, # 20099. I have included a link to the installation details for reference.

If you just need a replacement 2 wire switch, you can use Hopkins Replacement Break-Away Switch, # HM20010. On this switch, one wire splices into the electric brake wire coming from the trailer side connector. The other wire connects to the break away systems brake wire."


Hopkins LED Breakaway switch HERE

"LED indicator on breakaway switch lets you know the battery powered, emergency breakaway is engaged. If the plunger is removed the LED light is illuminated, indicating that there is power passing through the switch. 7" Long wires.

Features:

Durable pin and vehicle hook-up cable
Weatherproof design
LED test verifies power is being transferred to the trailer brakes
Light indicates that the breakaway circuit is engaged



Specs:

Works with Hopkins, Tekonsha and Tow Ready Breakway systems
7" Long installation wires
48" Long cable
90-Day warranty



A crucial component to a breakaway system, a breakaway switch is what activates the trailer brakes should your trailer become disconnected from the tow vehicle.


20059 LED Break Away Switch"

The ground is needed if you wish to use the LED light indicator which is built into the switch.

The LED lights up when the PIN is pulled to indicate if the switch is working and sending voltage to the brakes.

That's it, switch will still work fine even if you do not ground that extra wire, just don't expect the LED to light in that case.

[KD4UPL]

Lynnmor wrote:

Lwiddis wrote:
X2, Old Biscuit. After repair, test it! My life may depend on it working.

It’s not YOUR life if it is your trailer when it breaks free of the truck, you just drive away. Other users of the highway might want the trailer to do some braking, I guess that is what you mean.

Read his quote again. You and he are in agreement.



I see no reason for a break away switch to need a ground. It's just a simple single pole switch. I'm really curious why it would have/need a ground wire. I too would probably just swap it for a 2 wire so you are doing a direct replacement of the old one.

[Lynnmor]

Lwiddis wrote:
X2, Old Biscuit. After repair, test it! My life may depend on it working.

It’s not YOUR life if it is your trailer when it breaks free of the truck, you just drive away. Other users of the highway might want the trailer to do some braking, I guess that is what you mean.

[dodge_guy]

Old-Biscuit wrote:

dodge guy wrote:
Should only need 2 wires. One side goes to e blue brake wire and he other goes to battery positive. I've never seen one with 3 wires and I don't know why it would require a ground.

I would get a different switch with only 2 wires.

It's just a simple dedicated Ground Wire for Breakaway.
Connect to trailer frame

Not a big deal......

There is no reason for a traditional breakaway switch to have a ground wire. The switch Itself should Be isolated from the frame. I would highly question a 3 wire breakaway switch!

[donut_dave]

just bought and installed new breakaway switch. old one had 2 black wires and new one has 2 black wires. simple.

[Old-Biscuit]

dodge guy wrote:
Should only need 2 wires. One side goes to e blue brake wire and he other goes to battery positive. I've never seen one with 3 wires and I don't know why it would require a ground.

I would get a different switch with only 2 wires.

It's just a simple dedicated Ground Wire for Breakaway.
Connect to trailer frame

Not a big deal......

[dodge_guy]

Should only need 2 wires. One side goes to e blue brake wire and he other goes to battery positive. I've never seen one with 3 wires and I don't know why it would require a ground.

I would get a different switch with only 2 wires.

[Terryallan]

Kelpike wrote:
I recently purchased a 2003 25' Coachman travel trailer. The breakaway switch was crushed on the trailer so I replaced it but I am confused about the power for it. The old one only had 2 black wires coming out of it and going to a white and blue wire on the trailer. Those 2 go into the junction box in the trailer. The new one has 3 wires, blue, white, and black. First, what do I connect the black wire to? And second, it says make sure I disconnect the trailer plug before testing the breakaway. Does that mean it will draw power from my trailer battery?

Yes the breakaway / E brake uses the Trailer battery for power after the 7 pin come out. that is why most states require you to have a charged battery on your trailer.

and yes IF you pull the switch out while hooked to the TV. It can fry your brake controler

[opnspaces]

Most trailers the white is ground.
As far as your breakaway, the black goes to the positive post of the battery whatever color wire that is.

Here's a caveat. There should not be a disconnect switch between the brake controller and the positive or negative posts of the battery. The breakaway has to have a constant path to the battery that is never interrupted by a disconnect switch. This allows the switch to do it's job and stop the trailer in an emergency regardless of whether or not you remembered to flip the disconnect switch.

The breakaway does not draw any power until it is engaged (pin is pulled). The warning about disconnecting from the tow vehicle before testing the breakaway is to protect the brake controller. Some brake controllers can be ruined by 12v power feeding back up the brake wire when the emergency breakaway engages.