I Installed the Curt T-Connector Vehicle Wiring Harness # C56403 & Trailer Left Taillight Stays On

Updated 03/30/2025 | Published 03/20/2025

Question:

Hello, I installed the curt wiring harness on my tiguan. After installation, I noticed that the left tail light on the trailer is illuminated even when the car is off. checked all connections, and they seem good. Right taillight works as it should.

asked by: Korey P

Expert Reply:

Hello Korey,

I am sorry to hear that you got the Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # C56403 installed in your 2020 VW Tiguan and are having issues with the left tail light. Were you able to hook the trailer up to a different car to see if it does the same thing? I would check the ground on the trailer, that it is connect to a clean metal surface, having a bad ground can cause all kinds of wonky issues.

If you check that and everything appears to be fine, then the wiring could have a bad converter. I don't see an order on my end, did you get the wiring from us at etrailer.com?

expert reply by: Kate F

Korey P.

3/27/2025

Hello, I used a trailer light tester to eliminate the trailer. It’s still showing the same symptoms. I also unplugged the connectors from the taillights and still getting the same left taillight illumination. I have also relocated the ground with no success.

Kate F.

3/28/2025

@KoreyP Hey Korey. I hate to tell you this, but you have a bad converter which is why you are getting constant power back there. If you bought the wiring through us we can reship you a new one and send you a prepaid label to get that one back from you. If you purchased it from somewhere else you will have to contact that company. Please shoot me an order number if you did get it from us as I am not finding the order with your email.

Korey P.

3/28/2025

@KateF hello Kate, it was purchased through your site. The order number was 121777830.

Kate F.

3/30/2025

@KoreyP Hello Korey. Since the order was placed in November and is passed 30 days this will need to be handled as a warranty. Someone will be reaching out to you today about that process. If I can do anything else from my end please let me know. I am very sorry that you have to deal with this issue, but it is why companies have warranties on their items, every once in a while their is a bad seed. I hope you enjoy the rest of your weekend.