New to me Blue wire and Brakes

[w2much]

I just purchased a used 2005 Loadmaster trailer. The previous owner had it hooked up to a chevy P/U. I have a Bronco. My old trailer w/o brakes, had a 4 wire flat which went to a 6 wire round, all lights worked well. My new trailer has brakes and a five wire flat which I will also hook to the 6 wire round. I am new to trailer brakes and know nothing about them. What is the function of the blue wire? Is it lights only or does it activate the brakes. My Bronco has the factory trailer package which comes standard with the 6 wire round connecter. Hooked up my lights the same as my previous setup leaving the blue wire unattached.The lights did not cooperate. While connecting and disconnecting the harness I can hear something tick inside of the brake thing on the tongue. I don't have any knowledge of electric nor surge brakes. Would appreciate any imput. Thanks.

 

[tashasdaddy]

Re: New to me Blue wire and Brakes

you probably have surge brakes, the blue wire may the lock out solenoid, for backing. post a picture of the trailer coupler. if so the blue wire goes to the back up lights on the vehicle.

 

[Silvertip]

Re: New to me Blue wire and Brakes

fIf the trailer in fact does have electric (not surge) brakes, you need a brake controller in your vehicle. That controller senses how hard you are braking and sends the appropriate amount of current to each of the brakes. Without a controller, the brakes either would not work at all or if connected to the brake lights would lock up the wheels when you so much as touched the brake pedal. you can tell if you have electric brakes by looking at the back of each trailer wheel. If you see wires coming out of the backing plate you have electric brakes. If you see hydraulic lines like the ones on your car, you have surge brakes.

 

[4.0l sahara]

Re: New to me Blue wire and Brakes

If it's a 5 pin harnes with a blue wire it's a reverse soilinoid.

 

[tashasdaddy]

Re: New to me Blue wire and Brakes

this will help you. "http://www.accessconnect.com/trailer_wiring_diagram.htm"

 

[w2much]

Re: New to me Blue wire and Brakes

Thank You for your replies.Had a friend over and came up with your same replies. Spent the day on my back with an electrical tester,dirt falling in my face.My 6 prong round trailer adapter was wired for electric brakes. The controller has been in the truck under my dash since I purchased it. I purchased a new harness and will be installing it today weather permitting. Blue wire to the brake light. Thanks.

 

[Silvertip]

Re: New to me Blue wire and Brakes

So you are saying you have electric brakes? If you do, the brake wire does not go to the brake lights. The brake lights are on the yellow and green (turn signal) wires. The brakes are activated by a totally separate circuit from the brake controller.

 

[w2much]

Re: New to me Blue wire and Brakes

No, no. My Bronco was wired for electric brakes. Brakes on a trailer I never had. My new trailer has surge brakes with a reverse lockout solonoid. When I shift to reverse the brake light will go on the blue wire will be connected to them and will activate the solonoid on the trailer so that I may back up without having to get out and lockout the thingy.

 

[rodbolt]

Re: New to me Blue wire and Brakes

the blue wire is used as a reverse lockout.
if the connector is wired correctly the circuit taps the vehicles reverse lamp circuit when reverse is selected and energizes a solinoid just aft of the master cylinder and locks out the disc brakes by closing in fluid circuit.
otherwise disc brakes simply dont want to back up at all.
we also retrofit some drum brake applications with the same solinoid so the operator doesnt have to manually lock the brakes out for backing uphill.
most electric only brakes use a 7 or 9 pin connector.

 

[Silvertip]

Re: New to me Blue wire and Brakes

Either you are not writing what you are thinking or your thinking is wrong. The BRAKE light does NOT go on the blue wire. The BACK UP lights go on the BLUE wire which feeds the reverse solenoid which inhibits brake action in reverse. If you hook the reverse solenoid to the BRAKE light circuit the brakes won't work moving forward either as the solenoid would be engaged any time you step on the brakes.

 

[w2much]

Re: New to me Blue wire and Brakes

You are right I am wrong. But now I get it. Thanks.