KNOVA KN 8056, Manual

Page: 7 / 34

figure 8
Red
Black
Ground
Ignition
coil
figure 7
Red
Black
Ground
Ignition
coil
Multimeter Basic Testing
6
The RPM means the rotating frequency of the main
shaft of the engine per minute.
To test a diode out of a circuit, connect
the multimeter as follows:
1. Insert the red test lead into the terminal
and the black test lead into the COM terminal.
2. Set the rotary switch to .
3. For forward voltage drop readings on any
semiconductor component, place the red test
lead on the component’s anode and place the
black test lead on the component’s cathode.
The measured value shows on the display.
Note
• In a circuit, a good diode should still produce a
forward voltage drop reading of 0.5V to 0.8V;
however, the reverse voltage drop reading can
vary depending on the resistance of other
pathways between the probe tips.
• Connect the test leads to the proper terminals
as said above to avoid error display.
• The open-circuit voltage is around 2.7V when
testing diode.
• The LCD will display 1 indicating open-circuit
for wrong connection.
• The unit of diode is Volt (V), displaying the
positiveconnection voltage-drop value.
• When diode testing has been completed,
disconnect the connection between the testing
leads and the circuit under test.
E. Continuity Testing (see figure 6)
Never attempt an in-circuit current measurement
where the open circuit voltage between terminals
and ground is greater than 60V DC or 30V AC
rms.
To test for continuity, connect the multimeter as
below:
1. Insert the red test lead into the terminal
and the black test lead into the COM terminal.
2. Set the rotary switch to .
3. Connect the test leads across with the object
being measured.
The buzzer does not sound when the resistance
value is >50. The circuit is disconnected.
The buzzer sounds continuously when the
resistance value is 30W. The circuit is in good
condition.
Note
• The LCD displays 1 indicating the circuit being
tested is open.
• Open -circuit voltage is approx. 2.7V.
• When continuity testing has been completed,
disconnect the connection between the testing
leads and the circuit under test.
It was very important in the past to test the dwell of
the cut-off switch of an ignition system. The dwell
testing means the duration when the cut-off switch
remains off when the cam is turning. Now as an
automobile is ignited electronically, it is no longer
necessary to adjust the dwell. In addition, the dwell
testing can also be used to test a mixed-controlled
solenoid.
(e.g. GM feedback carburetor).
1. Set the rotary switch to DWELL .
2. As prompted at the LCD connect terminal,
insert the red test lead into the terminal
and the black test lead into the COM terminal.
Connect the ends to be tested as illustrated.
• If the cut-off switch of an ignition system is
tested, connect the red test lead probe to the
primary negative end of the ignition coil.
(Refer to the automotive servicing manual for
the specific position.)
• If the GM feedback carburetor is tested,
connect the red probe to the ground terminal
or the computer drive of the solenoid.
(Refer to the automotive servicing manual for
the specific position.)
• If the dwell of an arbitrary ON/OFF equipment
is tested, connect the red probe to the end of
the equipment, fixed with an ON/OFF switch.
3. Connect the black test lead probe to the good
ground terminal of the automobile.
4. Read the ignition dwell of the tested automobile
directly from the display.
To avoid possible damage to the multimeter
and to the device under test, disconnect circuit
power and discharge all high-voltage capacitors
before testing diodes and continuity.
WARNING
F. Dwell Testing (see figure 7)
G. Engine Tach (Rotation Speed) Testing
“RPMx10” (see figure 8)