Troubleshooting Trailer Lights Not Working with T-One Wiring Installed on 2020 Infiniti QX60

Updated 08/17/2022 | Published 08/15/2022

Products Featured in This Question

T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector

(225)

$80.55

Cordless Circuit Tester

(15)

$19.26

Question:

Good afternoon, I installed the tekonsha 4 pin trailer harness some time ago on my 2020 infiniti QX60 and up until this week, everything worked fine when I connected a trailer to it. Just yesterday I could not get the brake lights or signals to work but the running lights came on OK. I checked the relays and fuses as mentioned in a previous post link, but they checked out OK as well. Any other suggestions to look at? Also I replaced the full kit with a replacement kit I bought and I get the same results. Thanks again for the time and support.

asked by: SE

Expert Reply:

Thank you for all of the information!

The T-One Vehicle Wiring Harnesses, like part # 118670 for your 2020 Infiniti QX60, typically do a great job and don't malfunction often. Since you've replaced this harness already and you've checked and found your fuses to be good there is really only one other thing on the vehicle end that could be the problem and that's the OEM wiring on your vehicle (it's possible both T-One harnesses were bad but REALLY unlikely). What you'll do to test this is use a circuit tester like part # PTW2979 to see if all of the functions are there on your OEM connector that the T-One plugs into.

Another possibility is your trailer wiring is the problem. If the OEM connector on your QX60 tests alright then you can verify power is getting all the way to the 4-Way flat connector on the T-One by testing those pins as well.

If everything looks good on your vehicle then we need to check the wiring, connections, and grounds for all of the lights involved on your trailer, but if the problem is also affecting the lights on your vehicle then you'll need to take your vehicle to a shop and have it looked at.

Attached are some videos and a helpful article to assist.

expert reply by: Jon G