How to Install a 7-Way Trailer Connector on a 1998 Dodge Ram for a Brake Controller
Question:
I have searched through all of the FAQs online and NO ONE addresses the wiring at the plug. Evryone wants to push toward wiring the controller by just plugging it in under the dash but nothing is said about the other end of the wires. Where do I connect the wiring from the adapter at the bumper for the brake, power and back up? Where are these wires terminated at the back up the truck to connect the trailer plug to?
asked by: Carey S
Expert Reply:
If your 1998 Dodge Ram did not come with a factory 4 or 7-Way trailer connector, then you will need to first install Tow Ready Custom Fit Vehicle Wiring, # 118329. I have included a link to a video installation and a link to the installation instructions for reference.
You would then need to install a 4 and 7 Way Installation Kit, # ETBC7. We have a couple of detailed FAQ articles on this installation which I have linked for you. I have also included a video link showing a typical installation of an ETBC7 kit.
If your truck came with a factory 4-Way trailer connector, you will just need Adapter 4 Pole to 7 Pole and 4 Pole, # 37185, but it would be more beneficial to use ETBC7 because it comes with additional wire and circuit breakers. The brake (blue) wire does not run all the way back to the 4-pole at the rear; it stops at the connector that is located under the driver side wheel well. In order to finalize the installation you must splice into this wire and continue it back to the plug. But first, connect the white ground wire to the vehicle frame.
Using the duplex cable included with the ETBC7, connect the black wire on the connector to the black wire in the cable, and then connect the blue wire to the white wire in the cable. Route both under the truck, avoiding areas that may pinch or burn the wire. Connect the white wire to the blue brake wire on the truck in the location specified above.
Continue routing the black wire up into the engine compartment. Under the hood, you will connect the black wire to the positive battery terminal via a 40 amp circuit breaker.
The last wire (purple or yellow) will need to be connected to a reverse light wire behind one of the tail lights on the vehicle. After this connection, the 7-Way wiring will be complete and all that will remain is the connections for the brake controller.

Products Referenced in This Question
T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
- Custom Fit Vehicle Wiring
- Trailer Hitch Wiring
- Vehicle End Connector
- No Converter
- No Tow Package
- 4 Flat
- Plug and Lead
- Plug-In
- Visible
- Tekonsha
more information >
Adapter 4-Pole to 7-Pole and 4-Pole
- Trailer Wiring
- Wiring Adapters
- Multi-Function Adapter
- 4 Flat
- Plug and Lead
- 4 Flat
- 7 Round - Blade
- Hopkins
more information >
Universal Installation Kit for Trailer Brake Controller - 7-Way RV and 4-Way Flat - 10 Gauge Wires
- Accessories and Parts
- Trailer Brake Controller
- Installation Kits
- etrailer
more information >
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Instructions
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