Tow bar wiring kits and modules explained
Genuine Tow Bar Wiring Kit consists of a vehicle specific wiring harness and control unit with vehicle connectors and relays designed to fit and operate specifically with your vehicle. Most kits consist of a trailer control unit, loom with corresponding plug in connectors, power and communication cables, fully detailed vehicle specific pictorial instructions and a high quality 7 or 13 pin socket.
In addition you will also find a quantity of cable ties, fuses, and grommets necessary to complete the installation. Genuine Tow Bar Wiring Kits are better than universal kits, because dedicated kits are specially designed to work in harmony with your vehicle’s electronic system. Most will communicate with other vehicle control units to alter other vehicle settings accordingly.
This will also activate the dash trailer indicator warning light, deactivate parking aids and the rear fog lamps. These are model dependant features. Genuine Tow Bar Wiring Kits are generally not that difficult to fit, full and detailed instructions come with the kit. Fitting is usually done within a couple of hours and a coding is required with vehicle specific diagnostics tools. The benefits of a dedicated kit, is that when you tow the kit will alter the vehicle systems such as the trailer stability control program, suspension settings, traction control and anti-lock braking.
Genuine Tow Bar Wiring Kits operate three types of warning devices: audible beep, visual dash warning light when indicating and the original indicator warning light will flash at twice the usual rate when a trailer indicator has failed. In most cases, a dedicated kit will perform the full light functions after correct installation and a coding will not be required. However, if you wish to benefit from the additional safety features and other functions, then a recode may be required. Full coding details are included in the kit.
7-pin vs 13 pin wiring kits
|Features:||7-pin wiring kit||13-pin wiring kit|
|Turn signal lights||yes||yes|
|Rear fog light||yes||yes|
|Trailer turn signal light control||yes||yes|
|Permanent positive line||no||yes|
7-pin wiring kit
This wiring kit is the economic model with basic lighting functions for the trailer.
Connecting a permanent positive or charging line for additional functions in the trailer, and the (legally required) reverse light function with a cycle carrier, is not possible.
13-pin wiring kit
The 13-pin kit provides the option for further convenient functions such as lights in the trailer, refrigerator operation or reverse light with a cycle carrier.
This equips you for all situations from the start.
universal vs vehicle specific wiring kits
Universal wiring kits
Can be used on numerous different vehicle types:
- Offering complete support of the vehicles lighting system and some of the comfort functions (e.g. PDC, fog light switch off)
Vehicle specific wiring kits
Supporting the manufacturers vehicle warranty
A vehicle specific wiring kit is the recommended system for all modern vehicles. They provide you with all the benefits manufacturers code into their vehicle management systems to make towing a safe & reliable experience
- Activation of the vehicles TSP (Trailer Stability Program) helping to correct the ‘snaking’ action of a trailer
- Adapted braking settings providing optimal emergency stopping and enhanced assistance on hill starts
- Continuation of the vehicles light health check monitoring system to provide warning of any bulb failures
- Disabling of the vehicle‘s rear parking sensors to stop unnecessary and distracting ‘beeps’
- Disabling of the vehicle‘s rear fog lights (but not the caravan‘s!) to avoid distracting rear view mirror glare
- Adapted new gear ratio settings for automatic gear boxes to take account of the extra load being towed
- Disabling of the vehicle‘s stop / start economy feature to avoid stalling in unsafe locations
Other features that may be adapted include reversing cameras, adaptive cruise control, suspension systems and cooling systems