Troubleshooting Delay in Brake Lights Turning On When Applying Brakes in Tow Vehicle

Updated 07/19/2017 | Published 07/18/2017

Question:

Hello, Ive completely rewired a boat trailer with a 4wire flat wiring kit. Everything works except that i have a delay between when the brakes are applied in the tow vehicle and the brake lights come on the trailer. Its almost like they have to warm up slowly. What should I investigate as the culprit? I have cleaned up my grounds on trailer. Each light does have a dedicated ground wire running back to the front of the trailer at main ground

asked by: Josh

Expert Reply:

Since all of the ground connections have been verified and secured on the trailer, I next recommend using a circuit tester like # PTW2993 to test the brake light function on the vehicle side connector. Check to see if you get immediate power when applying the brake pedal. If there is a delay on the vehicle side connector, then the issue is somewhere on the vehicle side.

If the vehicle side connector tests fine, then I recommend simply running along the wiring on your trailer to make sure there are no damaged sections or anything that might be causing a short. You can also test the wiring along your trailer at different points to see if you can determine where exactly the delay in power starts when pressing on the brake pedal.

If you are unable to resolve the issue, please let me know and I will be happy to help you further.

expert reply by: Chris R