Troubleshooting My T-One Vehicle Wiring Harness On My 2018 BMW X#

Question:

Hi! I installed the trailer harness on my 2018 BMW X3. When I checked it using the little test light only the brake lights and the taillights work neither the right/left blinker or the 4 way emergency lights function the car lights are fine btw. Any thoughts?

asked by: Carl Y

Expert Reply:

There can be many reasons that your blinkers and your hazard lights are not working: your harness wires may not be connected securely, you may have plugs that are not seated together properly or making a good connection, you may require a fuse or a relay is blown or missing, or the ground may be insufficient. In order to troubleshoot your setup you will need a circuit tester. I recommend the Hook Probe Circuit Tester, part # PTW2993. There are four methods you will use to trouble shoot your wiring harness.

Testing for function
Verifying correct wire connections
Checking ground connections
Finding other possible issues

I have included a weblink that goes into more detail about this process, a video installation link of your T-One Vehicle Wiring Harness, a product description link, and a video review link of the circuit tester below.

expert reply by: Mark Smith