Lifan 720 (1.8 VVT) Electrical Instruction - page 2
5
Circuit Diagnosis
LIFAN 720
3 It means circuit fualt if light is not lit. If
using voltmeter and voltage display is
lower than the rated value with more than
1V, it means the circuit fault.
2.
Power Test
1 Disconnect the battery negative.
2 Connect one of the wire of the test light
with self-supply or the probe of the
ohmmeter to the component to be tested.
If using ohmmeter, please contact the two
probes each other and use reset button
to adjust the ohometer to zero.
3 Connect the other wire of the test light or
probe of the ohmmeter to the other side
of the load to be tested.
4 If the bulb is lit, it means the circuit is
continuous. If using ohmmeter, the
impedance value should be very small or
close to 0 Ω..
3. Short Circuit Test
1 Disconnect battery negative.
2 Connect one of the wire of the test light
with self-supply or the probe of the
ohmmeter to the outlet terminal of the
fuse.
3 Connect the other wire of the test light or
probe of the ohmmeter to the ground.
4 Disconnect all the loads to the fuse.
Note：If not disconnect all the loads to the
fuse, when testing the low impedance
circuit like lights, the ohmmeter will
always display the low impedance value.
This will cause wrong judgement.
5 Do the careful test from the place closest
to the fuse.
6 If the bulb is lit or ohmmeter has value
display less than 5 Ω., it means the short
circuit to the ground.
3
Switch
a1105005
5A
+B
0.5RD
0.5G
2 E00
1 E00
1 C00
I/P Fuse and Relay Box
Switch
Solenoid
Test Light
Voltmeter
a1105004
4. Voltage Drop Test
This is to test the voltage drop along the wire,
connector or switch.
1 Connect the positive probe of the
voltmeter to the end of the circuit close to
the battery (connector or switch side).
2 Connect the negative probe to the other
end of the circuit (the other side of the
connector or switch ).
3 Disconnect switch or connect it.
4 The voltmeter will display the voltage
drop between the two test points.
5 If the drop is more than 0.1 V (less than
50 mV for 5 V voltage circuit), it means
the circuit fault. Check loose, oxidation or
corrosion circuit.
Repair Tools
1. 5 KΩ Rheostat
It can simulate ohm-type sensor sginals, like
coolant temperature sensor, air intake
temperature sensor, etc. And help to make
quick adjustment on the performance of the
component.
2. LED Test Light
I/P Fuse and Relay Box
Switch
Selonoid
Voltmeter
5A
+B
0.5RD
0.5G
2 E00
1 E00
1 C00
a1105007
a1105008
a1105009
a1105010
6
Circuit Diagnosis
LIFAN 720
3
Bi-direction two-color LED light can change
its color when exchanging the positive and
negative. This feature can be used to test the
PWM control signals of Hall sensor.
3. Airbag Test Tool
Before installing a new airbag, plug this tool
to the airbag system, and use diagnostic tools
to test the airbag system to confirm it works
properly. After that, remove the airbag test
tool and install the new airbag. This process
can guarantee a safe airbag operation.
4. Probe
When testing a system component, insert this
tool into the connector from the back and do
not need to break the harness.
5. Terminal Repair Tool
When repairing the terminals, use this tool to
separate them from the connector.
a1105011
a1105012
a1105013
Terminal Repair
1. Remove the terminal pin.
2. Fix the clip with terminal repair tool.
3. Pull out the terminal from the rear of
connector.
a1105021
Terminal
Clip
Tool
a1105015
a1105014
7
Circuit Diagnosis
LIFAN 720
3
4. Clean and repair the terminals.
a1105016
Poor Ground Connection Repair
1. Remove the ground bolt.
2. Clean the two surfaces (both bolt side and
car contact side) of the copper ring with grit
cloth until the oxide completely cleared.
3. Clean the ground surface on the car with grit
cloth until it completely clean.
a1105017
a1105018
a1105019
8
Circuit Diagnosis
LIFAN 720
3
4. Install the harness and the bolt. Tighten to
specified torque.
Torque：M6 Bolts 8 Nm
M8 Bolts 20 Nm
a1105020
