Installation of Brake Controller on 2009 Volvo XC70 with Existing 4-Pole Wiring Harness

Updated 04/01/2016 | Published 03/30/2016

Products Featured in This Question

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

(3477)

$118.67

Question:

How hard is it to install a brake controller in a Volvo XC70 station wagon 2009 on my own? Ive already installed the trailer lights without issue but dont want to mess around with a brake controller? Also, I have a 5 pin lighting harness for our utility trailer. Is there a converter I can just plug in to take the five pin signal and convert it to a 7 pin RV ? Thanks!

asked by: Paul

Expert Reply:

Since you've already installed a 4-Way trailer wiring harness on your 2009 Volvo XC70, many of the wiring connections needed for a brake controller are already done.

The remaining connections that will be needed to hardwire install a brake controller are power wires to the positive battery post for the 7-Way connector and brake controller (routed through circuit breakers), signal wire from the 7-way connector to the brake controller for the electric brakes, tapping into the vehicle's dedicated stoplight circuit, and grounding the brake controller at the battery's negative post.

To make these connections and to provide your XC70 with a 7-Way connector, you will want to use the # ETBC7 kit. This kit includes all of the wiring and hardware needed to install the 7-Way and trailer brake controller. The vehicle-side connector included with the ETBC7 kit is a 7-Way and 4-Way connector. I have linked the installation instructions for the ETBC7 that will walk you through the installation. I have also linked an example installation video of this kit being installed on a Subaru Outback.

For a brake controller, I recommend he Tekonsha Prodigy P3 Trailer Brake Controller # 90195. This is a top of the line, proportional brake controller. The LCD display is customizable, easy-to-read, and user-friendly. Features of the P3 include storable settings for up to 5 trailers, 3 boost levels, battery protection, and continuous diagnostics.

It sounds like you're looking for an adapter that will allow you to connect the 5-way trailer-side connector on your utility trailer to the new 7-Way connector on your vehicle. To connect your trailer's wiring to the vehicle's wiring, you can use the Optronics 7-Pole to 5-Pole Flat # A75TB.

There is not an adapter that will allow you to adapt a 4-Way or 5-Way vehicle-side connector to a 7-Way connector and still have all of the functions of the 7-Way connector work properly.

I have also linked a help article on installing a brake controller from scratch for you.