Specifications

FCS1362 Page 21 of 74 © Nov 2010
o Avoid running cables in parallel
 Especially true for radio equipment antenna co-axial cables
• Where cabling is either open to the elements, or accessible within a vehicle, it will need protecting.
o Solid trunking will offer maximum protection to the cables where the vehicle type allows its use
o Spiral binding is flexible and easy to fit but probably least friendly for servicing equipment as it
may need to be unwound just to replace one cable. Over time spiral binding may retain, or
memorise, any bends in the loom thereby making it difficult to refit neatly once removed.
o Split trunking allows better cable access than spiral binding but can be unsightly if not fixed
properly.
It is best practice, where possible, for cables from equipment that carry low currents, i.e. signalling and
/or control connections but not power cables, to follow the existing vehicle looming. . This keeps wiring
intuitive and easy to find for servicing.
Taping up long lengths of cable looms with insulating tape is not acceptable on the basis of severely
hampering the ability to service or replace cables within the loom.
2.6.1.4. Connectors & joining cable
The connection type used will depend on how cables are to be joined together, joining into an existing
loom or cable, or joining two cables together end to end.
As a general rule plastic auto electrical snap lock splicing connectors that cut into the cable’s insulation
should not be used as a connection method.
2.6.1.4.1. Joining two cables
Suitable methods of joining cables include:
• Soldering
o this method requires more skill than crimping and so it is open to more mistakes.
o Soldering, particularly with gas powered irons, may not be allowed in certain environments.
Caution must also be taken where a gas soldering iron has a hot air vent which could easily
cause damage to the insulation of other cables or the environment around the area of use.
o Soldered joints must always employ a mechanical aspect, twisting cables together for
example, to give strength to the joint.
o The join should have any sharp elements such as protruding wires cut off, and the join must
always be covered to seal the whole joint using:
 Heat shrink tubing. This is the preferred method of insulating as it provides excellent all
round insulation and does not react badly to moisture or typical seasonal temperature
changes. Non-adhesive heat shrink tubing can be used inside a vehicle but it is
recommended to use an adhesive lined heat shrink tubing if the wire is exposed to the
elements.
 Self amalgamating tape. This can provide an excellent water tight seal and can
withstand exposure to many elements including corrosion and UV.
 Insulation tape which is then wrapped in a cloth tape. This will keep the insulation tape
in place over time but still provide excellent insulation.
It is not acceptable to attempt to seal a soldered joint by using insulating tape or a cloth tape on its
own. Insulation tape is prone to losing its adhesive properties over time and through exposure to
moisture and varying temperatures. Cloth tape, used in most automotive vehicles, is used as a
looming tape and is not an insulator. Cloth tape is designed mainly to create neat cable looms and
reduce the noise of these looms if they are in contact with any surface in a vibrating environment.
• Crimped (butt) connectors
o An acceptable method provided the correct size connector is chosen and the proper ratchet
tool is used
o These are only suitable for use inside a vehicle where the connector is not exposed to the
elements