3
2 INSTALLATION
2.1
Mounting the main unit
The Tow-Pro
®
Liberty should be mounted inside the vehicle cabin using either M4
screws or other secure fitting methods at the mounting points provided. It is essential
to mount the unit in a location which allows access to the intended remote head
location via the included remote head cable.
The Tow-Pro
®
Liberty can be mounted in any orientation
as long as the installation
is secure and the main unit cannot move or change orientation once installed. A
change of orientation will affect the system calibration.
Ensure that the Tow-Pro
®
Liberty is mounted securely in a fixed
location. Failure to mount securely will result in inaccurate braking force
measurements and incorrect braking of the trailer.
Ensure that the Tow-Pro
®
Liberty is installed inside the vehicle cabin and
away from any environmental conditions that may cause damage, including
engine heat, submersion in water, salt spray, dripping water and humidity.
Exposure to these conditions may cause damage to the unit’s circuitry and
may cause erratic trailer braking.
Do Not Mount to Cables / Wiring Looms
Any Secure Orientation OK
2.2
Wiring the brake controller
The Tow-Pro
®
Liberty is sold without a wiring harness.
REDARC Electronics manufactures a universal wiring harness, as well as a number of
vehicle-specific wiring harnesses for quick and easy installation.
For older vehicles not covered by our range of wiring harnesses where a custom
installation is required, the TPH-025 ‘Universal Harness’ should be used. Please follow
the subsequent instructions for all custom installations.
A Fuse or Circuit Breaker of appropriate rating must be installed to
protect the vehicle system. Please refer to the installation instructions for
specific instructions on where to install the Fuse or Circuit Breaker and
for appropriate Fuse or Circuit Breaker rating. The Fuse or Circuit Breaker
must be installed as close as possible to the battery.
Ensure that the wire(s) and all connections used to install the Tow-Pro
®
Liberty are suitably rated to supply the required current to simultaneously
operate the trailer electric brakes and stop lamps. Incorrect wiring can result
in reduced (or total loss of) trailer braking and/or damage to property or
persons.
2.2.1 Red Wire (Vehicle Brake light) Connection
The requirements for a suitable connection of a brake controller trigger wire are quite
specific. This connection point must:
•
Provide ‘Start Battery’* voltage output while the vehicle brakes are applied.
•
Have 0 volts output while the vehicle brakes are not applied
•
Accept battery voltage input when the brake controller manual over-ride is
operated and illuminate at least the trailer brake lights.
•
Accept the battery voltage input as above without causing any damage,
spurious vehicle operation or erroneous fault indication.
A relay should not be installed to drive the red wire as this would prevent the override
feature from working and may introduce dangerous voltage spikes.
For many vehicles, the brake light terminal of the trailer lighting socket provides
a suitable connection, however this is not necessarily suitable for all vehicles.
Unfortunately REDARC cannot recommend where to make this connection on a specific
vehicle’s OEM wiring. For further information contact the vehicle manufacturer.
* Start Battery voltage output means, directly from the Start Battery and within 0.4V of
Supply (Black wire) voltage.
2.2.2 Wiring Diagrams - Electric Brakes
The Tow-Pro
®
Liberty is designed to operate electric brakes in 12V electrical systems
only. For wire selection refer to the wiring gauge guide in Section 4.
The Input Power (Black) wire must be connected directly to the positive
terminal of the start battery via a Fuse or Circuit Breaker and not through
an Ignition source.
14AWG / 1.6mm²
To 12V Vehicle
Brake Light trigger
(refer to Section 2.2.1)
To 12V Electric
Trailer Brakes
Blue
Red
30A Fuse or
Circuit Breaker
(CBK30-EB)
12V Vehicle
Start Battery
Ground
Black
-
Dash mount
controls for
Tow-pro.
14AWG / 1.6mm²
12AWG / 3.0mm²
12AWG / 3.0mm²
White
2.2.3 Wiring Diagrams - Electric / Hydraulic Brakes
Always refer to the manufacturer’s specifications for your Electric/
Hydraulic Braking system prior to installation and usage of the Tow-Pro
®
Liberty.
Electric / Hydraulic Trailer Brake Systems
The Tow-Pro
®
Liberty is designed to operate both Electric trailer brake systems and
Electric / Hydraulic trailer brake systems. However, most Electric / Hydraulic systems
require a separate 12V power feed for the hydraulic pump. For example:
Electric / Hydraulic
System
12V Start Battery
Power Supply for
Electric/Hydraulic System
Output Wire (Blue)
Tow-Pro
Brake Signal
For wire selection refer to the wiring gauge guide in Section 6.
2.2.4 Wiring Diagrams - Vehicles with CAN Bus System
Many modern vehicles use a CAN Bus system for signalling when to apply the vehicles
brakes as required by safety systems including adaptive cruise control, stability
control, Autonomous Emergency Braking (AEB) and hill descent control. For these
vehicles, REDARC recommend the following wiring configuration.
White
To Vehicle Brake Light
Trigger
To Pin #6 of the
Trailer Plug
Blue
Red
30A Circuit Breaker
(CBK30-EB)
To Vehicle
Start Battery
Black
Dash mount
controls for
Tow-pro.
To Chassis Earth Bolt
Brake Signal Source
Brake Light Terminal of Trailer Plug
REDARC recommend sourcing the brake signal from the brake light wire of the trailer
plug as it will capture all braking events that illuminate the trailer brake lights.
Please note that if the brake signal is sourced at the trailer plug, a suitably rated* diode
MUST be fitted to the vehicles brake light wire on the vehicle side, the point where the
brake signal is sourced.
*The diode rating must at least match the total stop lamp(s) load on the trailer circuit.
Trailer Brake
Light Wire
from Vehicle
Tow-Pro Elite
Brake Signal Wire
Trailer Plug
Brake Light Wire
This prevents the back feeding of 12V into the vehicle when the Tow-Pro is manually
activated whilst illuminating the trailer brake lights.
Brake Pedal Switch
Sourcing the brake signal at the brake pedal will only detect braking events when
the brake pedal is depressed (and the switch activated) and not brake applications
activated by other on board systems such as AEB.
Note:
Only connect to the brake
pedal switch if specified by the vehicle manufacturer.
