One Side Of The Trailers Electric Brakes Are Locking Up

Updated 06/27/2017 | Published 06/25/2017

Products Featured in This Question

Digital Multimeter with 42" Long Test Leads - LED Display

(3)

$21.94

Dielectric Grease for Electrical Connectors, 2 oz.

(1478)

$10.94

Hook Probe Circuit Tester

(60)

$13.72

Question:

Worked fine before for several trips then hooked up to trailer to go home and left side of my tandem axle trailer brakes went up in smoke. Pulled over and unplugged trailer from 7 pin connector and brakes released. Controller is 6 months old. Trailer is 2012 forest river Salem 20foot purchased 6 months ago. Was able to limp home with no trailer lights or brakes. Havent pulled left wheels off yet to inspect damage.

asked by: JEFF F

Expert Reply:

The first thing you will need to do is ensure the breakaway pin is attached and the battery is fully charged. If you do not have a breakaway kit or the pin is still attached, please disregard. It sounds to me like the left side of your trailer's electric brakes are short circuiting. In order to test this, you will need a multimeter such as the 7-Function Digital Multimeter part # PT89ZR and a circuit tester like part # PTW2993.

You will first want to test each of the wires at the back of the connection on the vehicle side using a circuit tester. To do this, you will need a friend to sit in the vehicle and activate each of the trailer's functions while testing that wire to ensure a proper connection. If all of the wires are functioning properly, then the problem is on the trailer side. If the wires are not giving the correct reading, you will want to trace each wire back from the connector to ensure they are not split or short circuited.

The next thing you will want to do is test the wiring coming from behind the connector on the trailer. You will then want a friend to sit in the vehicle and activate the manual override switch on your brake controller. Once activated, test the brake signal wire, you should be getting a full 12 volts if the wire is attached properly. If you are not getting a full 12 volts at the back end of the trailer connector, you have a short in the brake signal wire and will need to trace backward from the connector to the left side brake ensuring you tape or seal all loose or severed connections. If you are getting a full 12 volts at the end of the trailer's connector, the problem may be in the actual connector. Check inside both trailer connectors for corrosion or loose connections in the back and reattach using some dielectric grease like the part # 11755. If all else fails, you will want to test the brake controller by probing each wire coming from the back of the controller in the vehicle.

It is likely that you may have caused extensive damage to your trailer's brakes and possibly hubs therefore, I recommend replacing those components while you have them disassembled. If you can tell me the axle capacity of your trailer's axles, I would be happy to offer my recommendation.

I have also attached our trailer wiring help article for you.