KNOVA KN 8056, Manual

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8
Diagnosis of automotive Troubles
12.60 V 100%
12.45 V 75%
12.30 V 50%
12.15 V 25%
E. Battery Power Consumption Testing when
the Engine Is off
The test is carried out to find the amperage of the
power consumption of the battery when both the
ignition key and the engine are off. The test is
helpful for the determination of the additional
consumption of the battery, which may finally lead
to the exhaustion of the battery.
1 Turn off and close the ignition key and all its
accessories. Make sure that the bus, engine louver
and room lights have been turned off and closed.
2 Set the rotary switch to A 10A. As prompted
at the LCD connect terminal, insert the red test
lead into the A terminal and the black one into
the COM terminal.
3. Cut off the link between the positive pole of the
battery and the cable and connect the test lead
probes to the circuit. (connect the red test lead
probe to the positive pole of the battery and the
black one to the cable.)
G. Voltage Drop Testing
Test the voltage drops caused by the switch,
cable, solenoid or connector. Any abnormal
voltage drop generally results from an additional
resistance. The resistance will restrict the currents
upon the start of the engine, leading to the
reduction of the load voltage of the battery and
the slow-down of the start of the engine.
1.Cut off the ignition system so as to disable
the start of the automobile.
Cut off the main ignition coil, shunt coil, cam and
starting sensor so as to cut off the ignition system.
Operate by reference to the automotive manual.
2. Set the rotary switch of the multimeter to the
200mV or 2VDC. As prompted at the LCD
connect terminal, insert the red test lead into the
V terminal and the black one into the COM
terminal.
3. Refer to the LOSS typical trigger voltage circuit.
(See the details in figure 9)
Test the voltage between any of the following pairs
of points respectively:1&2, 2&3, 4&5, 5&6, 6&7,
7&8, 8&9, 8&10.
4. Read the reading of the tested current directly
from the display with the normal current being
about 100 mA. For the special supply of currents
(when the engine is off), please refer to the
automotive servicing manual. If there emerges
any additional current, do necessary servicing.
F. Trigger Voltage Battery Load Testing
Upon the start of the engine, test the battery to
see if it can offer an adequate voltage.
1. Set the rotary switch to 20 VDC
2. As prompted at the LCD connect terminal,
insert the red test lead into the V terminal
and the black one into the COM terminal.
3. Interrupt the ignition system to disable the start
of the automobile. Cut off the main ignition coil,
shunt coil, cam and starting sensor so as to
interrupt the ignition system. Operate according
to the automotive manual.
4 Connect the black test lead probe to the
negative pole of the battery and the red one to
the positive pole of the battery.
5. Start the engine continuosly for 15 seconds
and the testing results are shown in contrast
as follows. If it is within the range, the starting
system is normal; on the contrary, it is shown
that there may be something wrong with the
battery cable, starting system cable, starting
solenoid or starting motor.
• Do not start the engine of the automobile
in testing or the multimetre will be damaged.
Compare the readings of the tested voltages
against the said table. If the voltage is on the high
side, check the components and connectors to
see if there is anything wrong. If anything wrong is
found, do necessary servicing.
• A fraquency-modulated radio or clock
needs a current supply of 100 mA.
WARNING
WARNING
Voltage Temperature
9.6 V or more 21.1º C (70º F)
9.5 V 15.6º C (60º F)
9.4 V 10.0º C (50º F)
9.3 V 4.4º C (40º F)
9.1V -1.1º C (30º F)
8.9 V -6.7º C (20º F)
8.7 V -12.2º C (10º F)
8.5 V -17.8º C (0º F)
Component Voltage
Switch 300 mV
Lead 200 mV
Grounding 100 mV
Battery Lead Connector 50 mV
Wiring 0.0 V
figure 9
LOSS Typical Trigger Voltage Circuit
Solenoid
Starter
Red
Black