A friend in the industry recently sent me an email concerning a 2011 Mercedes Benz E350 convertible (FW03303GTY).

He wanted to provide a heads-up about an issue with this vehicle that will affect glass technicians in the aftermarket arena. The vehicle is equipped with all of the options offered by Mercedes, including the Advanced Driver Assist System.

The company installing the replacement windshield used dealer glass, and they instructed the owner to take the vehicle to Mercedes for calibration. Before sending the car to the dealer, there were fault lights displayed on the dashboard, as expected. However, the Mercedes dealer discovered the installer had mistakenly switched the wiring connectors with other connectors.

According to the glass company representative, the dealership mechanic “checked the codes and was getting no communication from the LD camera, light sensor or overhead control module. In checking the wiring in that tight space (keep in mind, convertible) he found the connector to the module and camera were indeed swapped. They are the same style plug and will easily interchange. ”

The connector for the camera puts out a current to the camera’s internal heater. When the camera connector was plugged into the control module, the current from the camera connector was not proper for the control module, thus it shorted out the system.

The inadvertent mistake cost the glass company $1,500 to repair and replace the wiring harnesses and calibrate the system. With further research, we have found that Mercedes is not the only vehicle brand that uses interchangeable wiring connectors. Volkswagen is another manufacturer who uses these types of connectors in their door glass mechanisms.

Please take this as a piece of advice. Make sure – on German vehicles particularly – you pay attention to the wiring connections as you disconnect them. It may be necessary to mark the male and female ends to make sure you do not interchange them. It could cost you big dollars to fix a simple mistake.