Parts Needed to Install a Trailer Brake Controller on a 2003 Dodge Ram 1500

Question:

which wires do I splice into under dash 2003 dodge ram quad cab 1500 4x4 with tow package

asked by: Ryan J

Expert Reply:

If your 2003 Dodge Ram did not come with any type of trailer connector (7-Way or 4-Way) at the back of the truck, then there will be no wires to splice into under the dash to install a brake controller. You will need to hardwire in a brake controller using 3 items: a brake controller, a 4-Way wiring harness, and a 4 and 7 way installation kit # ETBC7.

For a brake controller I recommend the Tekonsha P2, # 90885, if you do not already have a controller. The P2 is one of our most popular controllers of all time because it works well, its reliable, easy to use, and easy to set up.

For a 4-Way trailer connector use # 119178KIT. I have included a link to the installation instructions for you.

After you have installed the 4-Way you can begin the ETBC7 and brake controller installation. The ETBC7 kit comes with all the wiring and parts you will need to hardwire in the controller. I have included some links that explain the ETBC7 installation for you.

If your truck already has a 4-Way trailer connector from the factory then you will need the brake controller, wiring harness # 3020-P and 7-Way # 37185. The 3020-P harness plugs in under the dash, to the left of the steering column, to a plug that is taped to another harness near the emergency brake pedal like in the video I have linked.

Also, 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 drivers side wheel well. In order to finalize the installation you must splice into this wire and continue it back to the plug. You will also need to run the 12 volt lead from the new 7-Way (black wire) to the battery via a 40 amp circuit breaker # PK54540. You can use wire # 10-2-1, sold in increments of 1 foot, for the extra wire needed.

And finally if your truck did have the factory 7-Way you would just plug in the 3020-P harness as described above, mount the controller, and plug the other end of the harness into the back of the controller.