Trailer Brake Help

biscuit · May 18, 2013

I have a tandem axle car trailer with electric drum brakes. I just recently put new backing plates with all new brakes and magnets on both axels. The trailer brakes have been working fine.

I just went to Harlan by way of West Virgina (buying axels) and the trailer brakes worked all the way to West Virgina. As soon as we left the guys house the brakes quit working. Just so you know US119 from West virgina to Harlan sucks without trailer brakes. Every now and then they would come on and then go off.

Got to harlan rode for the weekend and then before I left we made sure that the 12vdc was getting to the trailer. I had the 12vdc at the seven pin on the truck. Could not find any problem with the trailer.

Just before the cumberland gap we stopped. I looked over the trailer and found a wire pinched. I thought I found my problem. Cut the wire and then reconnected them with butt connectors. Left the parking lot and still no trailer brakes. Again every once in a blue moon they would come on and as soon as they would come on they would turn off.

When I got home I completely rewired the trailer and still no brakes. They are doing the same thing come on for a second or two then turn off. I am thinking that it could be my brake controller what do you think.

Any help would be much appreciated.

FroggF350 · May 18, 2013

Did you replace the plug too? I have had this happen to me 2 times, and it was the plug itself. The contacts where the wire bolts to the terminals was corroded, loose, and got hot. I replaced the plug for less than $10, fixed it.

Sawzall · May 18, 2013

I have had the same problem a couple of times. I had to replace the 7 pin connectors once and the controller another time.

Does your wiring have a ground between the trailer and truck? They don't need to rely on grounding through the hitch ball.

biscuit · May 18, 2013

Sawzall,

I have replaced the plug on the trailer as well. The wirign on the trailer is new from plug to tailights.

FrggF350,

Did you replace the 7 pin on the truck or the trailer? I have not replaced it on the truck. I do not have a acutal ground wire from the truck to the trialer but there is one in the seven pin plug if that is what you are asking.

I went and bought a new brake controller but before I go and replace it i wanted to make sure that might be the problem. I would hate to spend $90.00 on something that is not the problem.

FroggF350 · May 18, 2013

biscuit said:
Sawzall,

I have replaced the plug on the trailer as well. The wirign on the trailer is new from plug to tailights.

FrggF350,

Did you replace the 7 pin on the truck or the trailer? I have not replaced it on the truck. I do not have a acutal ground wire from the truck to the trialer but there is one in the seven pin plug if that is what you are asking.

I went and bought a new brake controller but before I go and replace it i wanted to make sure that might be the problem. I would hate to spend $90.00 on something that is not the problem.

Not likely that the truck side is bad, but is possible. I would borrow someone's controller before replacing it, it could be something in the pigtail from the controller to the truck

biscuit · May 18, 2013

I am going tomorrow to pull a buddy of mines trailer so if it acts up then i think it wil be the brake controller if not then it is something with the trailer. I will report back with wht I find. I must say the controller has been on there since 2001. It has been a good one.

biscuit · May 20, 2013

Ok I went yesterday and pulled my buddys trailer around and the brakes worked everytime i used them and stayed on. So i don't think it is my brake controller.

I lied about the trailer wiring. I forgot I did not replace the wire that goes throught the axel to the passenger side of the trailer brakes. I forgot about that for some stupid reason. I did make all new conections on the passenger side. I am going to replace the wire and see if it fixes my problem. I will report back.

zukiscott · May 21, 2013

We fixen to paint "GREMLIN" on the side of yo damn trailer Biscuit :****: ,,,,,hell yall practicly rewired that whole sumbitch in the macdonalds parkin lot the other mornin we was in Middlesboro for 2 hours looked like an episode

of overhaulin trailer wire style :spin:

......

Hell just take it to Drew and tell him to just put 4 wheel disc brakes on it with dual piston calipers and vented rotors and :flipgotcha:

some electric crap ;D

rideright · May 21, 2013

Sounds like a grounding problem. Check that there is no rust, paint or anything else between the wire that grounds the trailer and the trailer frame.

Sawzall · May 21, 2013

biscuit said:
Sawzall,

I have replaced the plug on the trailer as well. The wirign on the trailer is new from plug to tailights.

FrggF350,

Did you replace the 7 pin on the truck or the trailer? I have not replaced it on the truck. I do not have a acutal ground wire from the truck to the trialer but there is one in the seven pin plug if that is what you are asking.

I went and bought a new brake controller but before I go and replace it i wanted to make sure that might be the problem. I would hate to spend $90.00 on something that is not the problem.

I replaced both connectors at that time. You could tell that it had been arcing between the terminals.

biscuit · May 24, 2013

Ok here is the latest. I replaced the wires that I did not replace from the get go. Hooked up and still no trailer brakes. I then went and bought a new brake controller and still no trailre brakes. The new controller will tell you diffrent things and it says nothing is connected. I wiggled and jiggled the plug and nothing. So I hooked it up to a buddy of mines truck and the same thing not connected.

What would not make it see the trailer. i have checked my grounds and the wiring again and all seems correct?

badreligion_13 · May 24, 2013

biscuit said:
Ok here is the latest. I replaced the wires that I did not replace from the get go. Hooked up and still no trailer brakes. I then went and bought a new brake controller and still no trailre brakes. The new controller will tell you diffrent things and it says nothing is connected. I wiggled and jiggled the plug and nothing. So I hooked it up to a buddy of mines truck and the same thing not connected.

What would not make it see the trailer. i have checked my grounds and the wiring again and all seems correct?

I recenly had a similar problem. At the end of the day it was the plug. Can you take a voltmeter and check the brake on the truck side of the plug and then cut the wire on the trailer side and see if it is getting power through the plug? That is what I had to do to finally pin point it down to one of the female blades on the truck side of the plug.. It was smooshed into tight not letting it make good connect in the female side of the plug.. But, if you don't have power on the truck side of the plug then I suggesting checking fuses...or something is wired wrong.

cjunknxs · May 25, 2013

I had a similar issue on my dodge and it turned out being dirt being packed in where the electrical connector plugs into the truck side of the trailer plug. It took a lot of time with a test light to figure it out. I took a piece of mig wire and scraped the dirt out of it so it would plug in all the way and sprayed it with contact cleaner. If you are getting power to your brakes then it could be your magnets on your brakes. I hope you get if figured out, trailer brake/wiring can be a real pain, as you know.

biscuit · Jun 6, 2013

Ok I figured it out. I did have a short in the wire that ran through the axel tube. When my dumb ass replaced it instead of running the new hot wire across I ran the damn ground and the hot wire was not hooked up. Fixed that and all is good.

I fell like a complete dumb ass. oh well learn from your mistakes and go on.

Thanks everybody for the info.