Troubleshooting Low Voltage at Running Lights Pin with Curt Harness on Toyota Highlander

Updated 05/15/2018 | Published 05/12/2018

Question:

I hooked up a Curt wiring harness to my 2016 Toyota Highlander and everything works but the running lights. My multi-meter tells me that I have 6.6 volts coming out of the vehicle connector pin next to the ground pin. That is the correct pin for running lights, just not enough voltage to light the trailer bulbs. I would appreciate any idea that you may have.

asked by: Ned S

Expert Reply:

If you installed the Curt T-Connector Vehicle Wiring Harness # C56217 on your Toyota Highlander, I recommend making sure that the white ground wire from the harness is securely attached to a clean, bare metal surface. A weak ground can certainly cause the low voltage you are getting at the connector. The running lights will require more power draw than the other basic light functions, so this would explain why the issue is only apparent with them activated.

If the ground wire is securely attached and you are still having issues, I recommend using a multimeter and trying to test along the running light circuit wire from the connector and up along the vehicle, looking for where the voltage drops to see if the wiring might be damaged or exposed at any point.

If you are still not able to resolve this, please let me know and I will be happy to look into this further.

expert reply by: Chris R