Air conditioning system - function check

AP83.00-T-8352BAD

Air conditioning system - function check

21.2.05

 Danger!

Risk of accident caused by vehicle starting off by itself when engine is running. Risk of injury caused by contusions and burns during starting procedure or when working near engine

Secure vehicle to prevent it from moving.
Wear closed and snug-fitting work clothes.
Do not grasp hot or rotating parts.

AS00.00-Z-0005-01A

1

Start engine

 A minimum coolant temperature of
50 °C must be ensured.

2

Turn passenger compartment blower rotary switch (1) and driver area blower rotary switch (2) to stage 1

3

Press AC operation switch (5)

 The AC indicator lamp (6) lights up after approx. 20 seconds.

It is only possible to check the function of the air conditioning for its cooling capacity if the temperature in the passenger compartment is above 17 ° C.

Check refrigerant compressor

4

Turn driver area temperature rotary switch (4) and passenger compartment temperature rotary switch (7) to maximum cooling capacity setting

5

Open tailgate

6

Carry out visual inspection of refrigerant compressor

 When the engine is running and the air conditioning is operating, the clutch hub (18) must rotate.

7

Close tailgate

Check condenser fans

 Danger!

Risk of death caused by falling from vehicle roof. Risk of injury to other persons caused by falling objects during work in roof area.

AS65.00-Z-0002-01A

8

Carry out visual inspection of condenser (arrows)

 When the engine is running and the air conditioning is operating, the condenser fans (arrows) must rotate.

Check cooling capacity of the front box

9

Hold the sensor of the temperature measuring instrument in the air flow of the driver area ventilation and ascertain the temperature of the air flowing out

 The temperature of the air which flows out after approx. 5 minutes must be significantly below the outside temperature.



*WH58.30-Z-1002-08A

Check air recirculation flap of front box

10

Hold a sheet of paper to the grille (19)

 Get an assistant to help if necessary.

11

Press the air recirculation switch (3) alternately to determine the air flow at the grille (19)



Air recirculation mode:

 The paper must be suctioned.

Fresh air mode:

 The paper must not be suctioned.

Check front box radial fans

12

Turn driver area blower rotary switch (2) from stage 1 to stage 2 and then to stage 3

 The blower output of the radial fan must increase noticeably.

Check front box heat output

13

Turn driver area temperature rotary switch (4) to maximum heat output setting

14

Check temperature of air flowing out in driver area

 The temperature of the air which flows out after approx. 3 minutes must be significantly higher than the outside temperature.



*WH58.30-Z-1002-08A

Check cooling capacity of passenger compartment climate control

15

Hold the sensor of the temperature measuring instrument in the air flow at the air nozzles (8) and ascertain the temperature of the air flowing out

 The temperature of the air which flows out after approx. 5 minutes must be significantly below the outside temperature.

If necessary check the interior air filters for contamination and/or check the air conditioning system for leaks:



Air conditioning - cleaning the air filter for passenger compartment ventilation

AP83.30-T-8334BAC



Inspect the refrigeration circuit for leaks.

AR83.30-T-1209-01C



*WH58.30-Z-1002-08A

Check passenger compartment recirculated air flaps

16

Remove air recirculation filter for passenger compartment ventilation

AP83.30-T-8338BAC

17

Press air recirculation switch (3) alternately and check position of air flaps (9)



Air recirculation mode:

 Air flaps (9) are open.

Fresh air mode:

 Air flaps (9) are closed.

Check passenger compartment evaporator fans

18

Turn passenger compartment blower rotary switch (1) from stage 1 to stage 2 and then to stage 3

 The blower output of the radial fans must increase noticeably.

19

Close all open air nozzles (8) above seats in passenger compartment

20

Open one air nozzle (8) on the left and right side of the vehicle in the passenger compartment

21

Compare the air flows on the left and right side of the vehicle to each other

 If the power of the air flowing out is not the same:



Check function of evaporator fans on the weak side, replace if necessary:





Remove/install evaporator fans of air conditioning system

AR83.50-T-5050BAC

Check heating valve of passenger compartment climate control

22

Turn passenger compartment temperature rotary switch (7) to maximum heat output setting

 The AC operation switch (5) must be switched on otherwise the temperature in the passenger compartment is not controlled.

23

Open right rear luggage compartment flap

24

Check temperature of heating pipes (12)

 The heating pipes (12) for the convectors (10) must warm up noticeably.



*WH58.30-Z-1002-08A

25

Close right rear luggage compartment flap

Check convectors of passenger compartment climate control

26

Check temperature of convectors (10)

 The convectors (10) on the left and right side of the vehicle must warm up after approx. 3 minutes.



*WH58.30-Z-1002-08A

27

Turn off engine

28

Install air recirculation filter for passenger compartment ventilation

AP83.30-T-8338BAC

Number

Designation

WH58.30-Z-1002-08A

Digital temperature measuring instrument (measuring range -20° to +70°)