Brakes On Horse Trailer Do Not Operate and Lock Up When In Reverse on 2004 Chevrolet 3/4 Ton Truck

Updated 09/27/2010 | Published 09/26/2010

Question:

I HAVE A 2004 CHEVY 3/4 TON TRUCK AND WHEN I HOOK UP THE HORSE TRAILER,BRAKES ON TRAILER DOESNT WORK UNLESS YOUR BACKING UP AND THEN THEY LOCK UP. THANKS

asked by: DOYLE K

Expert Reply:

There is a possibility that the wiring going into your 7-way connector is wired incorrectly and that the brakes are connected to the reverse circuit. You will need to use a circuit tester, part # PTW2993 to test and make sure the wiring is run correctly into the 7-way connector. For this, you will need a helper, have your helper apply the parking brake of the vehicle and run the light, brake and reverse functions as you use the circuit tester on the appropriate wire for each function.

Many horse trailers use a 6-way connector, if you are using a 7-way to 6-way adapter you will want to make sure that it is wired correctly and test the wire functions. Also, check to make sure that the vehicle and the trailer are wired correctly (see FAQ).

If you are using a 7-way to 6-way adapter, there is a possibility that it is corroded on the inside and not operating properly and will need to to be replaced. The adapter you would need in this case, is the Adapter 7 Pole to 6 Pole, part # 47549.

expert reply by: Reno H