Troubleshooting 4-Pole Harness 118521 Installation in 2016 Honda Odyssey

Question:

I recently installed the following components on my 2016 Honda Odyssey so we can take out a tent trailer: ETBC7- Universal Installation Kit for Trailer Brake Controller 90195-Tekonsha P3 Prodigy 118521-Tekonsha Wiring Harness T-one connector Installation went well or so I thought. The controller shows the connection fine, and the trailer electronic brakes are whirring and no errors result on the controller, so I assume they work. The trailer running lights, brake lights, and turn signals are not working. I tested the 7 pin receiver end on my vehicle with a tester, and I have 12V power, but no none of the pins controlling the lights show a good connection. Does that mean I have a bad T-one connector? Is testing the wires on that the next step?

asked by: Austin S

Expert Reply:

Thank you for your purchase from etrailer of the # ETBC7 brake controller installation kit. This kit includes parts to install and wire the trailer brake controller of your choice, such as the Prodigy P3 # 90195. It does include a 7-way vehicle socket that plugs in to your existing 4-pole harness. I did not find any purchase history for a 4-pole harness, but Tekonsha part # 118521 is a correct fit.

You are correct that your next troubleshooting check will indeed be on the 4-pole set-up. That harness passes along the stop/turn/taillight signals to the 7-way so if they are not coming out of the 4-pole connector they cannot make it to the 7-way. To help you with troubleshooting the 4-pole I have linked both an install video for a 2016 Odyssey as well as a help article.

If you have a circuit tester like #PTW2993 you can use this to test the three lighting circuits on the 4-pole connector. The linked photo will show you on which pin to ground the tester, and on which pins to find the running light circuit and the left- and right-hand stop/turn signals.

You can also test the trailer lights directly by applying 12V battery power, from the Odyssey battery or another that is well-charged, directly to the lighting circuit contacts on the trailer's 7-way plug. You can refer to the linked image to see the ground and lighting circuit contacts to test.