BCM05-KIT – universal towbar wiring kits for monitoring the trailer's turn signals
The BCM05-KIT product line has been designed for the installation of towbar wiring harnesses in vehicles where the trailer socket can be connected directly to the vehicle’s electrical lighting circuits. This is the basic and necessary condition for using this kit. In such cases, the BCM05-KIT is a practical and economical solution, especially for typical, usually older vehicle models that are not equipped with advanced systems for monitoring the load of each lighting circuit.
BCM05-KIT sets include a complete wiring harness with a trailer socket, an indicator monitoring module and the necessary installation accessories. As a result, they provide a complete basis for installation by a specialized workshop, or even for self-installation.
Control of the operation of the trailer's turn signals
The core element of each kit is the BCM05 module, whose task is to detect faults in the trailer indicator light circuit. In the event of an indicator bulb failure, the module signals the fault with an audible warning, informing the driver that the trailer lighting is not operating correctly.
This is an important — and in some countries required — function from the point of view of driving safety. Properly functioning trailer indicators are essential for correctly signaling maneuvers, especially when driving with a cargo trailer, caravan, tow truck trailer or even a carrier connected to the towbar socket.
An innovative advantage of the BCM05 module is that there is no need to connect the module to a separate power supply directly from the vehicle battery. The module is powered from the vehicle lamp installation, which makes installation even simpler and reduces the scope of installation work almost to a minimum.
This makes BCM05-KIT sets a good choice whenever a simple, predictable and functional solution is needed to operate the basic trailer lighting, without the need to run an additional power supply line through the entire vehicle.
7-pin and 13-pin variants
The BCM05-KIT series includes variants designed for installations with both 7-pin and 13-pin sockets. This allows the kit to be selected according to the type of installation, the type of trailer and the expected range of lighting functions.
Available product variants:
(a) basic versions:
(b) versions with disconnection of the vehicle rear fog light:
54G variants – additional rear fog light function
The variants marked as BCM05-G7-54G-KIT and BCM05-G8-54G-KIT include a solution that allows the vehicle’s rear fog light to be disconnected after a trailer is detected.
This is a practical function, as it helps avoid a situation where the vehicle’s fog light reflects off the front wall of the trailer and remains unnecessarily illuminated while driving with a connected trailer. As a result, the installation operates more comfortably and is better adapted to the real operating conditions of the vehicle–trailer combination.
Complete kit content
Each BCM05-KIT set contains the elements required to complete the installation. The kit includes: the trailer indicator monitoring module, the main wiring harness for the socket, the trailer socket, an installation set, a screw set and a general installation diagram.
This equipment makes the installer’s work easier and reduces the need to source additional components separately. This is particularly important for workshops that expect a repeatable installation solution and simple technical documentation.
A wiring diagram is available for each variant, showing how to connect the harness, wire assignments, cable colors and the pin layout of the trailer socket. The technical documentation is especially useful for workshops installing towbars, as it allows them to quickly verify the connections, pins and wires responsible for individual lighting functions: indicators, position lights, brake lights, fog light and reverse light in the relevant kit variants.
Which vehicles are BCM05-KIT sets intended for?
BCM05-KIT sets are intended primarily for vehicles in which the trailer socket installation can be connected directly to the vehicle’s electrical lighting circuits. This most often applies to older or simpler vehicle models that are not equipped with advanced lighting self-diagnosis systems or systems monitoring the load of each lamp circuit.
Particular care should be taken when selecting a solution for vehicles equipped with self-diagnostic functions. BCM05-KIT sets do not provide separation of the power consumption of certain trailer lamps, which means that in vehicles with load monitoring, an error or fault warning may appear. For this reason, the selection of the kit should always be preceded by an assessment of the vehicle’s electrical installation. In case of any doubts, it is recommended to consult an experienced installer.
Why choose the BCM05-KIT line?
The BCM05-KIT line is a solution for users and workshops looking for a simple, functional and complete towbar wiring kit for typical applications. The BCM05 module provides trailer indicator monitoring and audible fault signaling, while not requiring an additional power supply from the vehicle battery.
The availability of 7-pin and 13-pin variants allows the kit to be matched to the type of trailer, while the 54G versions additionally extend the installation functionality by supporting the vehicle rear fog light disconnection after a trailer is detected. The complete kit contents and available wiring diagrams make the installer’s work easier and allow the installation to be carried out efficiently.
