Breakaway Switch Confusion.

NO....
It means if still connected to truck and breakway switch is closed it COULD (COULD) backfeed and cause issue with the Truck Brake Controller

As for the wiring----
the white is a ground wire, blue wire which will splice into the brake wire coming out of your trailer connector and a black wire which will connect to the breakaway box.

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

Old-Biscuit wrote:

As for the wiring----
the white is a ground wire, blue wire which will splice into the brake wire coming out of your trailer connector and a black wire which will connect to the breakaway box.

So my white out of breakaway gets grounded to trailer frame? Blue out of breakaway goes to trailer blue? And black out of breakaway goes to white out of trailer?

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.

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

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.

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......

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

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!

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.