2015 Volvo semi 7 Pin to 7 Blade RV Trailer Connector

Updated 08/29/2020 | Published 08/27/2020

Question:

Have a semi truck that I have mounted air actuated brake controller. Using blue from brake controller to 7 blade receptacle to trailer electric brakes. Using yellow for left turn and green for right turn. How do I convert the red brake Lights to work with the green and yellow. My trailer tail lights work with brake, turn and hazard on green or yellow wire. No separate brake lights

asked by: Marvin C

Expert Reply:

It sounds like you're wanting to install a 7-way blade trailer connector in addition to your 7-way round pin.

The easiest way to do this would be to use a 7-way adapter like # 37185 and a taillight converter like # 119178KIT. You'll tap the converter into the wiring harness feeding your 7-round pin connector. The yellow converter wire connects to the left turn circuit on the 7-round pin, the green converter wire taps into the right run circuit, the red wire into the brake lamp and the brown wire into the running lamp circuit. Once the converter's installed, you can plug its 4-pole into the # 37185. The white wire on the # 37185 would ground to the truck, the blue wire taps into the brake controller output, the black wire could connect to a 12V power source, preferably the positive battery terminal and the purple wire typically carries the reverse lamp circuit but it can be bundled up and tucked away if not needed.

This installation will combine the 3 separate brake lamp, right turn and left turn signal circuits into 2 circuits, one carrying right turn and brake lamp the other carrying left turn and brake lamp.

expert reply by: Mike L