Curt C51180 Echo Not Showing LED on 2020 Merceds Benz GLS 450 with 7 way Factory Connector

Question:

The Curt Brake Controller doesnt light up when I plug it to the 7 way connector in my 2020 GLS 450 ? I am not able to pair it

asked by: Rana S

Expert Reply:

If you're not getting a light on the LED whatsoever, it indicates that the unit isn't getting power through the trailer connector. Use a circuit tester like # PTW2993 on the pin in the 1:00 position in your 7-way trailer connector. If the connector isn't getting power on that pin, there's likely a fuse missing in the power distribution box in the engine compartment. You're looking for the 'Trailer 12V' or 'Trailer Charge' circuit. A fuse panel diagram wasn't shown in the online owner's manual copy I looked at, so you might need to check with your dealer about where that fuse might be located.

expert reply by: Mike L