Does Hot Lead for Both 4-Way Harness and 7-Way Connector Need to be Run on Vehicle

Updated 06/12/2018 | Published 06/09/2018

Products Featured in This Question

T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector

(265)

$86.29

Universal Installation Kit for Trailer Brake Controller - 7-Way RV and 4-Way Flat - 10 Gauge Wires

(3397)

$121.25

Question:

Im trying to install a 7 pin connector with brake controller and have purchased the 4 pin install tekonsha t-one and 7 pin conversion kit Hopkins as recommended for my 2017 Toyota Sienna. I noticed though that the 4 pin connection runs up to the battery as does the 7 pin. if I am doing the install all at once, can I skip the battery connection for the 4 way and only run the line for the battery from the 7 way connector? if not, can I combine the two wires and run them both through the same circuit breaker? I would love to see a wiring diagram that includes the 4 way, the 7 way adapter and the brake controller. it seems like there is some redundant work here and I dont want to accidentally connect something in the wrong place or have random extra wires running. Thanks.

asked by: John R

Expert Reply:

The Tekonsha T-One Vehicle Wiring Harness 4-Way Connector # 118648 for your 2017 Toyota Sienna does require that a hot lead be run to the vehicle battery. This hot lead is needed to power the converter for the 4-Way harness and will be separate from the power wire that needs to be installed for a 7-Way kit like # ETBC7. The 12V wire for a 7-Way is ran to the battery for the 12V pin at the connector. Both power wires will need to be run to the battery.

I also don't recommend running both wires through the same circuit breaker. Doing this will potentially trip the breaker anytime you are using both circuits, such as using the 12V circuit on the 7-Way to charge a trailer battery while also powering the trailer's running lights or turn/brake signals.

I have attached an article that details the installation steps when installing a 7-Way like you are from scratch that you might find helpful. I have also attached a wiring diagram for this type of setup that you can review.

expert reply by: Chris R