15
The Engine cut
(White and White/Red or White and White/Green wires)
There are two main means of immobilising a machine, the first and most common is by cutting a wire which is essential to
the running of the machine (DC cut method),
the second is by earthing out a signal wire so the ignition system cannot
create the spark needed for the engine to run (AC ‘earth out’ method). Which ever method is used the immobilisation
point should be made as inaccessible as possible. One immobiliser wire will always be unused depending on the method
of immobilisation. The spare wire should be removed from the alarm/immobiliser harness.
DC Method
Identify a wire which is critical to the engine operating but which is carrying less than 7 amps and cut it. With modern
machines it is normally wise to use either the dedicated immobilisation points provided by the manufacturer or to use an
engine safety interlock (e.g. Side stand switch, Kill switch, Fall over sensor, etc). Other circuits, such as the fuel pump
relay, ignition pack, coils, etc, may be used but refer to the manufacturers manual before using these circuits as they may
cause the machine to log running faults.
Where possible remove a section of the original cable and rejoin this wire via the White and White/Green wire. These
wires are non-directional so it doesn’t matter which wire of the alarm is connected to which end of the cut wire.
Important notice: Canbus based machines
It is recommended on canbus based machines that the only circuit cut
is the wire between the kill switch and the ECU. Other points of immobilisation are likely to create fault codes. Most
Canbus based machines are equipped with a transponder immobiliser as standard.
Critical notice: Transponder immobilisers/Thatcham approval
More machines are now being equipped with
transponder immobilisers as standard. However many of these machines are not Thatcham approved to category 2
standards.
When selecting whether a machine can be equipped with an S4 red (alarm/immobiliser) or S4 Green (alarm upgrade) this
MUST be taken into account. The S4 Green product only gives insurance benefits if fitted onto a machine already
complying with category 2 immobilisation. Please visit
www.thatcham.org
for the latest listings or contact Datatool.
The wire to be immobilised is cut and rejoined via the White and White/Green wires.
The White/Red wire is not used.
Cut and insulate the White/Red wire
or remove it from the harness
Wire being immobilised
is cut
Alarm
Harness
Connect the White/Green wire to
one side of the wire which has been
cut to immobilise the machine
Connect the White wire to the other
side of the wire which has been cut
to immobilise the machine
