A wiring harness kit for trailer couplings electrically connects the trailer and the towing vehicle. Wiring harnesses are classified into 7-pin and 13-pin models. Both models are available as vehicle-specific or universal wiring harness kits.

Vehicle-specific wiring harness kit
A vehicle-specific wiring harness kit is customized to the particular vehicle type. It features the following advantages:

• Compact plugs can be connected directly to the vehicle-specific connector of the rear lights or to other predefined interfaces. Thus, the installation time is significantly reduced, and possible  mistakes concerning the connection are eliminated.
• Control devices, socket and passage grommet of the vehicle-specific wiring harness are exactly customized to the electronics of the vehicle supply system and the vehicle geometry. Length and installation of the cables have been developed to perfectly fit the particular vehicle. This guarantees short installation time and flawless functionality.
• The included installation material enables a professional installation and is suited specifically to the vehicle type.
• The installation manual clearly describes the installation kit at hand and all necessary work steps in text or picture.

Universal wiring harness kit
A universal wiring harness kit is applicable in different vehicle models and types. Dependent on vehicle dimension, an expert has to individually adapt the wiring harness to each vehicle. The universal wiring harness kit features the following attributes:

• An expert has to determine the vehicle cable to which the wiring harness can be connected via snap lock connector. While connecting, the expert has to consider the cable width to avoid cable damage.
• Control devices, socket and passage grommets are designed for a broad functional and geometrical area. Cable lengths are planned generously. Adaptations of the wiring harness kit by an expert may be necessary due to vehiclespecific features.
• The installation material covers every standard installation. Vehicle-specific requirements have to be supplemented by additional material.
• The installation manual describes a standardized installation procedure. Vehicle-specific features are not indicated separately. An expert should carry out theinstallation.