# Trailer Brakes



## Livin4weekenz (Aug 26, 2007)

We returned home today from our first camping trip of the season from Pocomoke State Park in MD. It was a great weekend. However, on the ride home the trailer brakes failed. The P3 brake controller read "warning no trailer brakes" "battery short". After checking the fuse in the truck and checking the coupler, I am at a loss. I could not figure out why or where the short occurred. This is the first trip we have used this brake controller. It worked fine going down. And 30 miles into the trip home. It did start to pour down rain right before the brakes went. I did make one quick stop. All around the same time. After I got home, I shut everything off and plugged it back up. Brake controller says now no trailer connected. Lights and all still work. Is there a fuse on the trailer? Has this ever happened to anyone else? Please give any advise or help. Thanks!!!


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## CamperAndy (Aug 26, 2004)

The lights are not on the same circuit as the brake control and there is not normally a fuse on the brake power wire from the controller to the brakes.

What is the resistance from the trailer plug brake wire to ground?


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## Carey (Mar 6, 2012)

If you pull the pin on the emergency cable away from its box.. What happens? Just wondering.. Trailer shouldnt move with pin pulled..

If it moves, you got an open circuit on your main brake signal wire between the connector and the connector that sends the signal to the 4 brakes.

Inside the junction box at the nose of the trailer is often a problem..

Measure voltage at the truck plug too. Just to rule out your truck..

I dont know how many brand new trailers I have picked up and hit a few bumps and lost the brakes.. 90% of the time they didnt make a good connection where the trailer cable is joined in the junction box..

Prolly every 3rd trailer I pick up has some funky wiring problem.. By the time I get it delivered, I have gotten it fixed, so I dont even mention it.. My fix will outlast the trailer anyway..

Makes a guy mad when one second you have brakes and the next second you dont on a trailer with 20 miles on it..

Again, these things are built buy the illustrious Gilligan and that equates to workers from a far away land south of the USA..

Carey


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## swanny (Oct 31, 2007)

I didn't have any problems with the power to the 5ver. But I'm sure i would have after checking the connections in the junction box. Two of the connections just came apart with very little effort. I cut all the connection off and wire nutted them myself. Check the box


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## Livin4weekenz (Aug 26, 2007)

CamperAndy said:


> The lights are not on the same circuit as the brake control and there is not normally a fuse on the brake power wire from the controller to the brakes.
> 
> What is the resistance from the trailer plug brake wire to ground?


When I check the resistance from the trailer plug to ground my tester reads "OL" I assume this means "open line" there is no connection between the two. should there be?

when the kids are asleep I will get the wife out to check the truck voltage ,she will be in the truck moving the manual bar over while I check the truck connection.


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## CamperAndy (Aug 26, 2004)

Livin4weekenz said:


> The lights are not on the same circuit as the brake control and there is not normally a fuse on the brake power wire from the controller to the brakes.
> 
> What is the resistance from the trailer plug brake wire to ground?


When I check the resistance from the trailer plug to ground my tester reads "OL" I assume this means "open line" there is no connection between the two. should there be?

when the kids are asleep I will get the wife out to check the truck voltage ,she will be in the truck moving the manual bar over while I check the truck connection.
[/quote]

OL is bad and indicates a broken connection.

Next you need to move to the 4 square box that the pig tail connects into and find the connection there that goes to the brakes. Check from there to ground. resistance should be about 2 ohms. If it is open there you need to move to each wheel and check each wire to each brake to ground.


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## Livin4weekenz (Aug 26, 2007)

CamperAndy said:


> The lights are not on the same circuit as the brake control and there is not normally a fuse on the brake power wire from the controller to the brakes.
> 
> What is the resistance from the trailer plug brake wire to ground?


When I check the resistance from the trailer plug to ground my tester reads "OL" I assume this means "open line" there is no connection between the two. should there be?

when the kids are asleep I will get the wife out to check the truck voltage ,she will be in the truck moving the manual bar over while I check the truck connection.
[/quote]

OL is bad and indicates a broken connection.

Next you need to move to the 4 square box that the pig tail connects into and find the connection there that goes to the brakes. Check from there to ground. resistance should be about 2 ohms. If it is open there you need to move to each wheel and check each wire to each brake to ground.
[/quote]

Thanks I'll try that in the daylight tomorrow hopefully it is a easy fix


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## DernMooseAK (Apr 16, 2004)

Same thing happened to me last year on the way back to AK. My problem was the brake wires running through the axle tube. After a rain, got trailer not conected. Had all the trailer lights, just no brakes.
After checking every connection on the trailer, and all truck fuses. I decided to pull on the wire running into the axle tube. Got the connected light. So i cut one end and pulled the wire out to find the axle had water in it, and the wire had several bad cracks in it. so I cut out the bad section and spliced back to gether. Zip tied the wire to the out side of the axle to get home and has worked every since. Still need to rerout the wires, either in side the axle or another rout.


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## Carey (Mar 6, 2012)

swanny said:


> I didn't have any problems with the power to the 5ver. But I'm sure i would have after checking the connections in the junction box. Two of the connections just came apart with very little effort. I cut all the connection off and wire nutted them myself. Check the box


Yep Swanny, I carry a whole bag of them thar wire nuts..

DernMoose.. Great handle... Made me laugh!

Too bad Andy isnt closer.. He'd have that baby fixed up in no time!

Sounds like its for sure the trailer to me..

Carey


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## TwoElkhounds (Mar 11, 2007)

I had a similar problem last year with my trailer brakes. I eventually found the short inside the one of the brake drums. There is a wire clip inside the drum that routes the wire to the solenoid. The clip is bare metal and has sharp edges. It eventually chaffed through the wire insulation and created an intermitent short.

First thing I would do is pull your drums and inspect each of these clips.

DAN


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## Livin4weekenz (Aug 26, 2007)

I took the outback and the truck in to the dealer Friday morning not five minutes go by and the guy comes out to tell me the problem is with the truck









Now I don't claim to be a wire nut but I know how to use a multi tester.

I checked every fuse and relay no problems

with my multi meter I go to the plug on the back of the truck and put one probe on the brake pin the other on the ground pin when I slide the hand brake lever on the P3 the voltage reads from 0-12.8 (GOOD)

Wen the brake is applied I get 4-5 volts which is OK because it is parked set to max, It is inertia based so I wont get a 12.8 unless the whole deal is in motion and the comes to a sudden stop right?(GOOD)

Then I hook the trailer up and check voltage at the work box (I taped the hand brake to max) 12.8 (GOOD)

There is a black wire that leaves the work box and goes under the trailer for the brakes check that wire 12.8(GOOD)

I go under the trailer there are 4 wires that drop down two sets one for each axle check voltage there 00 (NOT GOOD)

What happens to the little black wire that goes under the trailer to turn it into 4 I do not know I can only assume there is i break in there some where







( is it just a wire nut ?)

also when I pull the emergency cord nothing no lock up nothing.









with the rally days away







tomorrow morn I will be back at the dealer he needs to show me how he thinks its the truck!!

I may have do the repair myself . I really don't want to mess with that underbelly stuff


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## CamperAndy (Aug 26, 2004)

Quick fix.

Splice into the black wire that leaves the 4 square work box and disappears under the trailer and run a wire from there back to where it drops out of the belly and branches to the brakes. Splice it in there and you are fixed. There is most likely a missing/loose wire nut in the belly.


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## Livin4weekenz (Aug 26, 2007)

CamperAndy said:


> Quick fix.
> 
> Splice into the black wire that leaves the 4 square work box and disappears under the trailer and run a wire from there back to where it drops out of the belly and branches to the brakes. Splice it in there and you are fixed. There is most likely a missing/loose wire nut in the belly.


I like it







but each drum has 2 wires and I assume 1 is ground the other is + and I think there the same color green


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## CamperAndy (Aug 26, 2004)

Livin4weekenz said:


> Quick fix.
> 
> Splice into the black wire that leaves the 4 square work box and disappears under the trailer and run a wire from there back to where it drops out of the belly and branches to the brakes. Splice it in there and you are fixed. There is most likely a missing/loose wire nut in the belly.


I like it







but each drum has 2 wires and I assume 1 is ground the other is + and I think there the same color green
[/quote]

One is ground and one is power even though they are both the same color (not polarity sensitive). Check them to see which is wired to ground and connect the brake power to the other.

You may want to pull down the belly on the street side near the axles and peek in there. you may see where the wire has come loose.


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## TwoElkhounds (Mar 11, 2007)

I have had a similar problem. In my case, the problem was a shorted wire in the brake drum. For some reason, they use metal wire clips inside the brake drums to secure the wires. These chafe the wires and cause shorts.

DAN


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## Livin4weekenz (Aug 26, 2007)

CamperAndy said:


> Quick fix.
> 
> Splice into the black wire that leaves the 4 square work box and disappears under the trailer and run a wire from there back to where it drops out of the belly and branches to the brakes. Splice it in there and you are fixed. There is most likely a missing/loose wire nut in the belly.


CamperAndy is my new hero








the rain stopped long enough to try your idea







all systems go!
Just in time we leave for the rally tommorow.









Thanks John


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## 'Ohana (May 20, 2007)

Livin4weekenz said:


> Quick fix.
> 
> Splice into the black wire that leaves the 4 square work box and disappears under the trailer and run a wire from there back to where it drops out of the belly and branches to the brakes. Splice it in there and you are fixed. There is most likely a missing/loose wire nut in the belly.


CamperAndy is my new hero







the rain stopped long enough to try your idea







all systems go!
Just in time we leave for the rally tommorow.









Thanks John
[/quote]

Hip Hip Hurray !! for CamperAndy and I'm glad to hear that all systems are a go









See ya @ DB tomorrow

Ed


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## Sayonara (Jul 23, 2007)

Thats great news !! CamperAndy comes through again!! 
Be sure not to forget about the permanant fix when you get back.

Enjoy the Rally !!!


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## CamperAndy (Aug 26, 2004)

Sayonara said:


> *Be sure not to forget about the permanant fix when you get back.*


This is the best advice.


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