Troubleshooting Brake Lights After 4 to 5 Way Flat Adapter Installation

Published 11/08/2019

Products Featured in This Question

Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector

(88)

$43.80

Hook Probe Circuit Tester

(62)

$13.33

Question:

got a t-connector and 4 to 5 flat adaptor, all lights work, but when it sit for a few miutes brake lights dont work , I unplug light and plug back and works, sits a few minutes and brakes dont work again help..

asked by: Tony

Expert Reply:

When all but one light functions fine, the issue can sometimes be that the harness is not connected securely or there's an insufficient or short to a ground on either the trailer vehicle side. There are other potentials as well but to start let's follow these steps to troubleshoot.

Test at the 4-way plug with a circuit tester # PTW2993 for correct functioning. I have included an instructional video of what steps to take. If any function does not have correct power, test the wire going into the converter box from the vehicle side. If the functions are correct, proceed to testing the trailer. Next test behind the converter box and if any of the functions do not have correct power, look for loose wires, connectors not secured, or loose/weak ground connection.

The included Help Article also provides troubleshooting techniques to try.

expert reply by: Patrick R