Specifications

FCS1362 Page 22 of 74 © Nov 2010
• Heat shrink splicing
o These come in two types and have a heat shrink outer casing making them acceptable in
areas where the connector may be exposed to the elements
o They generally follow the same colour code for wire size as standard crimps, i.e. red, blue and
yellow
o Crimp versions require the correct crimp tool to be used before the outer casing is shrunk
using a heat gun.
o Solder versions are self contained with pre fluxed solder within a transparent heat shrinkable
tube.
 They just require a heat gun to fit
 Combine a soldered, strain relieved, encapsulated termination for weather proofing
and can be used on sensitive low temperature wires such as PVC.
• Specialist crimp connectors
o Many specialist connectors incorporating crimped connections in a clamped housing are
becoming available and some vehicle manufacturers specify these for any connections into
the vehicle wiring loom.
o These connectors can offer strain relief and protection against the elements.
2.6.1.4.2. Joining, or cutting into an existing loom or cable
This is typically the case when sourcing an ignition sense or ignition feed within the vehicle.
When joining into an existing cable the only acceptable method of joining is to solder. This method
requires a reasonable amount of skill and so it is open to mistakes if care is not taken.
Soldered joints must always employ a mechanical aspect, twisting cables together for example, to give
strength to the joint.
• Cut around 20mm of insulation from the cable being tapped into and tin the conductor.
• Twist the new tap wire around the exposed conductor and solder.
• Any sharp elements such as protruding wires should be cut off.
• Seal the joint with self amalgamating or insulation tape wrapped in a cloth tape as described in
section 2.6.1.4.1 above.
2.7. Connecting to vehicle data bus
Many vehicles now incorporate an on board data network such as CAN bus and don’t have a
conventional ignition sense signal. Here the use of CAN bus interfaces or adapter modules, sometimes
plugged into the OBD-II socket, may be the only means of acquiring an ignition sense signal. These
modules provide a switched sense output by interpreting the CAN bus data.
The vehicle manufacturer should be referred to before connecting into the CAN bus and any interface
devices should be compliant with the requirements in section 2.2, i.e. the interface module must carry ‘e’
mark certification, so as to retain the safety integrity of the data bus.
If it is necessary for an install to require joining into the existing CAN bus loom without the use of an
adaptor it should be done using the method described in section 2.6.1.4.2.
2.7.1. Single Vehicle Architecture
A project known as the ‘One Box’ ‘Single Vehicle Architecture Project’ (SVA) is, at time of publication of
FCS1362:2010, nearing completion.
This SVA Project, which is supported by the emergency services and manufacturers, is intended to
create a standard vehicle infrastructure. A vehicle complying with the SVA Criteria will have, in essence,
an intelligent distributed power supply and a control network using the Emergency Services Control Area
Network (EsCAN).
SVA invokes some constraints on installation:
• SVA allows only a small range of industry standard connectors to be used