How to Add Flat Tow Capable Wiring to a School Bus

Question

Question:

I have a school bus that needs trailer wiring for flat towing a car. My bus currently does not have any trailer wiring. The bus’s brake lights and turn lights are separate wires. But the 7 and 4 pin vehicle side receptors that I see necessitate the turn lights and brake lights to be connected to same pin? Right turn/stop. Left turn/stop. I don’t plan to use any electric brakes, but just want towed car to have working brake, turn, running lights and a power line for charging the battery. Thanks for your help!

asked by: Tyler M

0

Expert Reply:

Hey Tyler, thanks for the information and welcome back. To add wiring to your school bus you'll need to install the Tekonsha Tail Light Converter with 4-Way Flat Trailer Connector item # 119178KIT. This kit includes the powered converter, a circuit tester to help you identify the wires for connection and the quick-splice fasteners.

The converter included with the Tekonsha item # 119178KIT will combine the separate stop and turn functions on the 4-pole output side. These combined signals will be carried on the green and yellow wires, right and left respectively.

You can then install the Adapter 4-Pole to 7-Pole and 4-Pole item # 37185. You'll plug the 4-way directly into it from the item # 119178KIT. You'll then need to install the Roadmaster Battery Charge Line Kit for Motorhomes item # RM-156-75. This will connect directly to your bus's battery and connect to the 12v circuit on the 7-way.

These two harnesses will allow you to control your flat tows wiring functions and power a charge line.

What vehicle are you setting up to flat tow and do you need recommendations on parts?

You can add this information, along with any other questions you have, where it says Add Comment.

expert reply by: Jerred H

0

119178KIT
(click to enlarge)

Tom F.

2/16/2026

The expert reply by Jerred H pretty much says it all really well. I installed the parts referenced on a 2006 Jetta, for towing a small home build trailer. Since I am not too good with electronics, I just watched the installation videos on etrailer concerning the parts I purchased, and followed the installation instructions. Everything worked perfectly. For technical support, I would refer you to etrailer. Their techs are really good. Tom

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Answer 2

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How to Add Flat Tow Capable Wiring to a School Bus

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