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The 12 volt positive ignition switched supply
(Brown tagged wire)
This wire stops the alarm from arming when the ignition is turned ON. It also is used to pull the immobilisation relay
contact together when the system is disarmed and the ignition is ON.
It is important the wire remains positive when all the machines controls are operated. Should the power fall away from
this wire the machine will cut out. For this reason we advise you connect to an ignition switched positive supply which is
run critical. In this way if the power to this wire fails the machine would stop anyway and therefore supply taken becomes
as safe as the machine itself.
One exception to this is using a kill switched controlled ignition supply. Should this supply be used it is O.K. but it must be
explained to the customer that the immobiliser will arm if the kill switch is turned to OFF.
Many installers use other circuits (e.g. the rear brake light supply). Whilst this will work it should be realised if the fuse
blows to this circuit (possibly due to a fault on the machine itself) the machine would stop and as the OE fuse blown is not
related to the running of the machine in the standard form the customer may not find it easily.
On some machines many of the ignition switched positive circuits turn off whilst the starter button is being operated to
reduce the load on the battery. This is particularly true of lighting circuits. Therefore it is extra important the 12v Ign LED
on the test box is checked to ensure it does not go out whilst cranking. If everything works fine through the test box but
when you connect the alarm the machine fails to start, this is the probable cause.
Should you choose to combine your ignition switched supply with the immobilisation of the machine it again is important
you observe the 12v Ign LED remains lit when you press the STARTER and ENGINE cut buttons of the test box. If it
goes out, then the Brown tagged wire has been connected to the wrong side of the immobilised wire and
MUST
be moved
or the machine will not start when connected to the alarm and the alarm will not commission.
On certain machines if you choose a different ignition switched supply to the one recommended by Datatool (e.g. Aprilia
canbus based models) there may be a few seconds delay before the lit goes out. This is quite normal on this type of
machine and simply delays the arming period of the alarm by the time it takes for the ignition control relay of the machine
to reset. If the machine has this feature most manufacturers recommend the ignition is not turned back on until after the
ignition has automatically reset. With these types of electrical systems, turning the ignition OFF and then immediately
back ON may, in extreme circumstances, cause faults on the machine. If you are unsure please refer to the
manufacturer’s manuals.
However if the 12v Ign LED remains lit at all times with the ignition turned off the Brown tagged wire must be moved.
Failure to do this will stop the system from operating as it will think the ignition is still turned on.
