Lifan 620. Manual — part 78

4) Dust deposit or deformation of heater fins, and poor ventilation—clean or replace the heater;
5) The hot-water pipe of heater is blocked by scale deposit—replace the heater;
6) Insufficient engine cooling water—check whether leakage exists in cooling system, repair it and
replenish cooling water;
7) Failure of engine thermostat—replace the thermostat;
8) Air exists in the heater core barrel—expel air in the pipe.
ii. Fault diagnosis table of air conditioning system

Table 6-2

new one.

High pressure is low,

low pressure high

2. Air duct is blocked.

Adjust jaw opening of expansion valve or

replace with a new expansion valve.

1. Stop the machine, low pressure

increases quickly—system ice plug.

Replace with a new drier-receiver.

High pressure is low,

low pressure negative

2. Stop the machine, low pressure

increases slowly—system ice plug.

Clean the system.

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Table 6-2 (Continued)

Phenomenon & state

Cause analysis

Measure

1. Inlet air cleaner is blocked.

Replace with a new inlet air cleaner core.

2. Air duct is blocked.

Clean air duct.

3. Evaporator surface dust

Clean the evaporator surface.

Normal

voltage

4. Blower motor works stagnantly.

Inspect the blower motor, or replace with a

new one.

Insufficient

air output

②

③

④

⑤

Fully open the vehicle door.

314

iv. Refrigerant injection, as shown in Figure 6-38.

②

④

②

315

316