Troubleshooting Trailer Brake Lights Not Working When Connected to Tow Vehicle

Updated 07/03/2017 | Published 06/30/2017

Question:

Hooking trailer to Lexus es 330

asked by: Danny

Expert Reply:

To try and determine the issue you'll first want to find out if the problem is on the trailer or vehicle side. Use a circuit tester, like # PTW2993, at the Lexus's trailer connector and test each pin. If everything checks out the issue is on the trailer side, and you'll need to inspect its connector and wiring for any corrosion or damage. Also make sure the ground connections are clean.

If the problem is on the vehicle side, then check its trailer connector and make sure it's clean. Also make sure there aren't blown fuses related to towing or a trailer. Then inspect the wring starting at the connector and working towards the point where it's connected to the vehicle's wiring. Make sure it's connected to the correct circuit as well.

If you still can't find the issue let me know and we'll keep troubleshooting.

expert reply by: Charles S