Adapting a 4-Way Trailer Connector to Tow a Trailer With Brakes and a 7-Way Connector

Question:

I have a 2000 nissan frontier which has only 4-way wiring for trailer hookup. the trailer i have borrowed, however, has the 7-way plug, and has brakes. I have purchased an adapter which allows me to plug the 7-way into my 4-way, but i am neglecting three extra wires which support brakes, backup lights, etc. Is this hazardous? The guy at Oreily told me he thought the trailer would do some weird stuff like lock up the brakes if i dont connect them. i have driven the trailer around the block and it seems fine. What do you think?

asked by: Anderson B

Expert Reply:

The trailer has brakes because the weight of the trailer requires them for towing it safely. The brakes will not lockup when not connected to the vehicle in any way. It will definitely be safer if you put a brake controller in your vehicle and either run the wiring for a 7-Way connector or put a 5-Way connector, # 47515, at the rear of the vehicle and connect it to the trailer 7-way connector with an adapter you build yourself using these parts, # PK12707 and # 20017 . I personally would wire the 7-Way connector and a brake controller and be done with it.

For the 2000 Nissan Frontier you can use the # ETBC7 trailer brake installation kit along with any of our brake controllers(see link). I recommend the Tekonsha PRODIGY, item # 90885, which is a very good controller and gets excellent reviews.

Take the 4-Way connector already on your truck and plug it into the 4-Way at the rear of the connector supplied in the kit. Then all you have to do is run the remaining three wires that you need. If you do not need one of these three wires just use a wire tie and tie it up out of the way. There is also a ground wire that will need to be attached to a suitable grounding point on the vehicle frame. The blue wire will run forward to the blue wire coming from the brake controller, the black wire will run forward through a 40-amp circuit breaker, # PK54540 included, to the positive post of the battery. The purple or yellow wire is run to the reverse light circuit if needed.

You then need to install the brake controller. Ground the white wire on the brake controller to the negative post on the vehicle battery. Run the black wire on the brake controller to the vehicle positive post through a 20, # PK54520 or 30, # PK54530, amp circuit breaker. The brake controller instructions will tell you which size circuit breaker to use. Next, run the red wire to the vehicle stop light circuit behind the stop light switch on the vehicle. Use a circuit tester, # PTW2993, to determine which wire has power when only the brake pedal is depressed. Once this wire is located and the red wire is connected to it, all that is left is to connect the blue wire to the wire from the 7-way connector out back and use the brake controller instructions to set up the controller for towing.

expert reply by: Robert G