Troubleshooting Taillights for Trailer Wiring on 2012 Volkswagen Touareg

Updated 03/31/2021 | Published 03/29/2021

Products Featured in This Question

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

(28)

$79.94

Computer Safe Logistic Probe

(8)

$19.28

Question:

I have a t reg here with your harness and the left side turn and brake light are not working. Can you give me a detailed wiring diagram for the 4 pole and 7 pole to mate with this supplied harness. I have no signal out of the black box to the black with green tracer wire which is suppose to operate the trailer lights for the left side.

asked by: CORY L

Expert Reply:

I have attached the installation instructions for # 118668 below. I do recommend using a Circuit Tester # PTW2991 for testing your connections. This will help ensure your ground connectors are working properly as well.

I do not see a black wire with green tracer coming out of the black box. The black wire is the 12V constant power. Your output wires are green for right turn/brake, yellow for left turn/brake, brown for running lights and white is ground.

I hope this will help you identify where the problem is occurring. It is also a good idea to check all the connections both on the wiring and vehicle to ensure none of the pins bent, broke or pushed out of their connector.

expert reply by: Bud M