jcb JS300 Service Manual page 615

Wires 000-199, 1000-1999
These numbers are reserved for ignition feeds, heater start
circuits and start circuits. These can be further categorised
by:
– Wires 000 - 099 are allocated to unfused ignition
feeds.
– Wires 100 - 199 and 1000 - 1999 are allocated to
fused ignition feeds.
Note: Feeds via ignition relays are classed as ignition
feeds.
Note: Can also include power supplies output by ECU's.
Wires 200-399, 2000-3999
These numbers are reserved for battery feeds, They can
be further categorised by:
– Wires 200 - 299 and 2000 - 2999 are allocated to
unfused battery feeds.
– Wires 300 - 399 and 3000 - 3999 are allocated to
fused battery feeds.
Note: Can also include power supplies output by ECU's.
Wires 400-599, 4000-5999
These numbers are reserved for instruments, sensors and
variable input/output signal wires used in electronic
systems. CANbus wires also use numbers in this series.
Wires 600-799, 6000-7999
These numbers are used for earth wires. When the
number is printed onto a wire A it is prefixed by the Earth
K Fig 31. ( T
symbol B. C-190). This symbol is printed
onto the wire, it may however be omitted from harness
drawings.
Fig 31.
C-190
Where a load is switched negative, the wire number from
the load to the switch shall be different to that of the wire
from the switch to the earth.
Wires 800-999, 8000-9999
These numbers are reserved for switched supplies to
electrical loads, i.e. to lights, etc.
Note: Can also include power supplies output by ECU's.
Wires In Splices
The main input wire is allocated with a wire number and a
suitable description, i.e. Wire 640, earth splice. The
additional wires in the splice are allocated the same wire
number and a
K Fig 32. ( T
C-190).
Note: The letters I, O, Q and S are not used.
General Points
Wires continue to have the same number even after
passing through a connector block to another harness.
The descriptions are applicable to JCB specification wiring
harnesses. The machine may be fitted with some wiring
that does not conform to the JCB specifications, typically
when it is part of equipment supplied by other
manufacturers.
9813/5100-1
Section C - Electrics
Harness Systems
Wire Numbers and Functions
postfix, i.e. 640A, 640B,
Fig 32.
etc.
T011680-C1
C-190