How to Install Trailer Wiring 7-Way on Older Truck with Separate Turn Signals from Brake Lights

Published 10/23/2018

Products Featured in This Question

Hopkins Trailer Connector Adapter - 7-Way RV Style Blade Plug to 7-Pole Round Pin

(124)

$36.19

ZCI Circuit Protected Vehicle Wiring Harness w/ 4-Pole Flat Trailer Connector and Installation Kit

(521)

$192.62

Adapter 4-Pole to 7-Pole and 4-Pole

(659)

$61.47

Tekonsha Prodigy P2 Trailer Brake Controller - 1 to 4 Axles - Proportional

(2763)

$159.00

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

(3397)

$121.25

Question:

I have an older truck 1955 that has separate wiring for the brake lights and turn signals. The turn signals are controlled by an ad-on unit clamped to the steering column. The turn signals are different bulbs than the brake lights. How do I connect to a 7-pin connector and a newer trailer that uses the brake lights and turn signals in combo with the same bulb?

asked by: Martin S

Expert Reply:

You'll first need to install a 4-way on your truck that is designed to take separate turn signals and convert them to combined. For that you'd want the part # 119250KIT which will give you a 4-way that has combined circuits.

Now if your trailer does not have brakes all you would need is the part # 37185 as an adapter to convert the 4-way to a 7-way.

If you do have trailer brakes you would need the # ETBC7 instead of the # 37185 and a brake controller. This kit comes with everything needed to wire up the 7-way and install a brake controller.

For a brake controller I would recommend the Prodigy P2 Brake Controller part # 90885. This is our bestselling brake controller because of how well it works and how easy it is to setup.