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activating components with a positive (+) Voltage within vehicle electrical system
5.6.
5.6.1.
Set up the tool as shown in fig.14 and set to voltage mode.
5.6.2.
contact the probe tip to the positive terminal of the component, the test indicator should illuminate green. Whilst observing the test
indicator, quickly press and release the power switch forward to the positive position. if the indicator changes instantly from green to
red the tool is ready for use.
5.6.3.
if the circuit breaker activates, the unit has been overloaded. this could happen for the following reasons:
a) the tip's contact went to direct earth.
b) the component has a short circuit.
c) the component is a high current component (i.e. starter motor)
warning! randomly applying voltage to certain circuits can cause damage to a vehicle's electronic components. it is
‰
strongly advised to use the correct circuit diagram and diagnostic procedures whilst performing this test.
5.7.
Activating components with a negative (-) voltage within vehicle electrical system
5.7.1.
Set up the tool as shown in fig.15 and set to voltage mode.
5.7.2.
contact the probe tip to the negative terminal of the component, the test indicator should illuminate red.
5.7.3.
Whilst observing the test indicator, quickly press the power switch rearwards to the negative position and release it. if the indicator
changes instantly from red to green the tool is ready for use.
5.7.4.
if the circuit breaker activates, the unit has been overloaded. this could happen for the following reasons:
a) Where the tip of the tester has contacted is a direct positive voltage.
b) the component has a short circuit.
c) the component is a high current component (e.g. a starter motor) (8Amp max.)
warning! with this function a vehicle's fuses may blow when the probe tip is earthed in series with them.
‰
5.8.
checking For bad earth contacts
5.8.1.
With the tool connected to the battery supply, set to the voltage mode.
5.8.2.
Probe the suspected earth wire or contact with the probe tip. observe the colour of the test indicator.
5.8.3.
Press the power switch forward to the positive position and release it. if the test indicator changes from green to red, this is not a true
earth. if the circuit breaker tripped when the power switch was pressed forward, this circuit is more than likely a direct earth. note that
high current components such as a starter motor will also cause the test indicator to trip off during this check.
5.9.
Following and Locating short circuits
5.9.1.
in most cases a short circuit will appear by a fuse or a fusible link blowing or an electrical protection device tripping (i.e. a circuit
breaker).
5.9.2.
connect the tool to the battery supply. remove the blown fuse from the fuse box. use the probe to activate and energise each of the
fuse contacts. The contact which trips the probe circuit breaker is the shorted circuit. Take note of this wire's identification code or
colour.
5.9.3.
follow the wire as far as you can along the wiring harness. for instance if you are following a short in the brake light circuit you may
know that the wire must pass through the wiring harness at the door sill. locate the colour-coded wire in the harness and expose it.
5.9.4.
Probe through the insulation with the probe tip depress the power switch forward to activate and energise the wire. if the circuit
breaker tripped you have verified the shorted wire.
5.9.5.
cut the wire and energise each end with the probe. the wire end which trips the circuit breaker again is the shorted circuit and it
will lead you to the shorted area. follow the wire in the shorted direction and repeat this process until the short is located.
5.10.
voltage Differentials
5.10.1.
the red/green LED's will only illuminate when the voltage at the probe tip is within ±0.8Volts of the supply battery voltage. This is a
useful feature for some fault finding procedures.
5.10.2.
if the circuit voltage is not within ±0.8Volts of the supply battery voltage, the LCD screen will display the voltage figure at the circuit but
no LED's will illuminate. This will indicate a difference of ±0.8Volts between the supply battery voltage and the voltage in the circuit
being tested. remove the probe tip from the circuit and press the power switch forward. the lcd screen will now display the
-supply battery voltage. the difference between the supply battery voltage and the circuit voltage can now be determined.
5.11.
using with sensitive circuits
5.11.1.
the led's and the lcd screen draw no more than 1mA current ensuring that the tool is safe for use as a multimeter or test light on
sensitive ecu controlled electronic circuits such as the airbag circuit.
© Jack sealey limited
fig.14
Original Language Version
fig.15
PP100.V2| Issue 1 13/06/17
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