3.4.
POLARITy TESTING. (See fig.3)
Contacting the tip of the probe to a positive (+) circuit will light the led indicator Red. Contacting the tip of the probe to a negative (-)
circuit will light the led indicator GReen. Contacting the tip of the probe to an open circuit will be indicated by the fact that the led
indicator is off.
3.5.
CONTINUITy TESTING. (See fig.4)
By using the probe tip together with the auxiliary ground lead, continuity can be tested on wires and components which are
disconnected from the vehicle’s electrical system.
3.5.1.
When continuity is present, the led indicator will light GReen.
NOTE: DO NOT press the power switch.
3.6.
fOLLOWING AND LOCATING SHORT CIRCUITS:
In most cases a short circuit causes a fuse to blow or a circuit breaker to trip
and this is the best place to begin the fault tracing process.
3.6.1.
Remove the blown fuse from the fuse box. Hold the probe tip against each of the contacts in the fuse box in turn whilst moving the
power switch to the forward, single bar position. The side which causes the LED indicator to turn off or causes the unit to sound is the
shorted circuit.
3.6.2.
Note this wire’s identification code or colour. Follow the wire as far as you can along the wiring harness.
3.6.3.
locate the colour coded wire in the harness and expose it.
3.6.4.
Probe through the insulation of the wire with the probe tip and move the power switch to the forward, single bar position to energise
the wire. If the LED indicator turns off or the unit sounds you have identified the shorted wire.
3.6.5.
Continue testing the wire at each connector in the harness. The wire which causes the LED indicator to turn off or causes the unit to
sound will lead you to the shorted area. Inspect the harness for signs of chafing or burnt out wiring and replace or repair as
necessary.
3.7.
ACTIVATING COMPONENTS REMOVED fROM THE VEHICLES ELECTRICAL SySTEM. (Such as fuel pumps, starter
solenoids, magnetic clutches, blower motors, cooling fans, lights etc.) See fig.5.
By using the probe tip together with
the auxiliary ground lead, components can be activated, thereby testing their function.
3.7.1.
Connect the auxiliary ground lead’s clip to the negative terminal of the component to be tested. Contact the probe to the positive
terminal of the component. The led indicator should light GReen indicating continuity through the component.
3.7.2.
Whilst keeping an eye on the green illuminated led, quickly rock the power switch forwards to the single bar position and release it.
If the green indicator changes instantly from GReen to Red, you may proceed with further activation.
3.7.3.
If the green indicator went off at that instant or if the unit sounds, the unit has been overloaded. This could happen for the following
reasons.
a) Where the tip of the tester has contacted is a direct ground or a negative voltage.
b) The component is short circuited.
c) The component requires a high amperage (e.g. a starter motor).
NOTE:
When the unit sounds, a circuit breaker within the unit will trip. This breaker will reset automatically within 3 to 5 seconds.
fig.3
fig.4
fig.5
fig.6
P
PLK Issue 3 12/02/19
Original Language Version
© Jack Sealey limited
