Trailer Brakes Locked Up

[MotorCityBear]

I will check the wiring on the truck and trailer for a mis-match and hopefully I just need to change a few wires in the trailer. I know the trailer brakes work, as they locked up as soon as I plugged it into my truck and released as soon as I unplugged them.
Thanks for the help!
Rob

 

[aczlan]

I will check the wiring on the truck and trailer for a mis-match and hopefully I just need to change a few wires in the trailer. I know the trailer brakes work, as they locked up as soon as I plugged it into my truck and released as soon as I unplugged them.
Thanks for the help!
Rob

if there is a mismatch, I would use the wiring diagrams found above to make it so that both sides match the standard. That way another vehicle can tow your trailer or you can tow another trailer with your truck.

Aaron Z

 

[4570Man]

There was a thread here I think it was years ago. It was a four way stop intersection that a 1500 series truck pulling a trailer went thru and hit a car. The truck driver said he tried to stop but the weight of the trailer pushed him thru. The skid marks for the trailer were dashed, similar to a broken crossing line on a highway only black rubber skid marks, whoever had wired the trailer up had wired the lights to the turn signal circuit and the brakes would pulse with the turn signals. The driver said he had never needed to panic stop since he had the trailer and never noticed it before..............Mike

I gotta call bs on that one. First problem is with no controller and straight 12 volts the brakes will be locked. He never noticed the trailer brakes being applied every time the turn signals blinked? Yea right. Next problem is the trailer brakes are way higher amperage than the turn signals and would have probably blown the fuse after the first application leaving you with no trailer brakes at all.

 

[MotorCityBear]

So I checked the truck and it is wired identical to the picture REPowell posted(thanks for the pic). So I guess that is right.

I need to start checking the trailer now but holy crap, it is like 41 degrees and windy. I am in GA, what the heck is going on with the weather!

 

[aczlan]

I gotta call bs on that one. First problem is with no controller and straight 12 volts the brakes will be locked. He never noticed the trailer brakes being applied every time the turn signals blinked? Yea right. Next problem is the trailer brakes are way higher amperage than the turn signals and would have probably blown the fuse after the first application leaving you with no trailer brakes at all.

I have to disagree. We towed a 7,000# trailer behind our Dodge 1500 that was wired with the turn signals to the brake wire.
No fuses blown, just brakes every time we turned on the turn signal.

Aaron Z

 

[Mancelona Man]

Not sure on Chevy.... but my Nissan Frontier had the brake wire and constant 12 volt for break away battery reversed. I had to cut and splice in the wire harness under the truck and crisscross them.

 

[4570Man]

I have to disagree. We towed a 7,000# trailer behind our Dodge 1500 that was wired with the turn signals to the brake wire.
No fuses blown, just brakes every time we turned on the turn signal.

Aaron Z

But you noticed right away right?

 

[mrmikey]

gotta call bs on that one.

Just what I read and saw in the pics of the skid marks.

 

[aczlan]

But you noticed right away right?

We picked it up from a friend's house, didn't notice till we got half way home. Probably wouldn't have noticed it as much if it had been empty.

Aaron Z

 

[Dftodd]

What's kind of common as well is someone not familiar with the color codes between a 4 pin and 7 pin plug. They tend to apply a 4 wire color code to the 7 pin which will make your trailer lights go wonky as well.

Yellow is aux power (battery charge) on a 7 pin, red is left turn, brown is right turn, and green is parking lights.

You get someone used to wiring 4 wire plugs and it gets interesting. Especially when they are using a trailer light that comes wired for a 4 pin connector.

They plug it in and the left light stays on all the time, right turn will cause both lights to blink. Left turn won't do anything, and parking lights will turn on the right light. :laughing: