Troubleshooting 3rd Brake Light Not Working on 2019 Mazda CX-5 After Installing Curt T-Connector

Updated 11/25/2019 | Published 11/24/2019

Question:

I installed the 65377 harness on 2019 Mazda CX-5 , the tail lights work on vehicle , but not on the hatch. Not sure why

asked by: Tom H

Helpful Expert Reply:

You might want to go back through and trace the steps that you took when installing the Curt T-Connector # C56377 on your 2019 Mazda CX-5 to see if you accidentally forgot to plug something in or if maybe some wiring got damaged. Since the tail lights are working properly I don't see how the T-Connector would be affecting the 3rd brake light but if everything looks fine you might as well disconnect the tees from the Curt wiring harness and plug everything in like it was prior to installation the trailer wiring kit. If your 3rd brake light works properly then the T-Connector is somehow disrupting the signal and you'll want to replace it. Otherwise you'll need to take your CX-5 to your local dealer or qualified mechanic so they can help you identify what's wrong.

expert reply by: Jon G