Air conditioning system - function check

AP83.00-T-8352BAS

Air conditioning system - function check

4.2.03

 Danger!

Risk of accident as vehicle may start off by itself with the engine running. Risk of injury as working around the engine during start-up or while running may result in contusions and burns

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 coolant temperature of at least 50 °C must be guaranteed.

2

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

3

Press AC operation switch (5)

The AC indicator lamp AC (6) must light up.

The function of the cooling capacity can only be checked if the temperature in the passenger compartment is above 17 °C.



Check refrigerant compressor

4

Rotate rotary controller for driver area temperature (4) and rotary controller for passenger compartment temperature (7) to maximum cooling capacity

5

Open rear lid

6

Carry out visual inspection of refrigerant compressor

 The clutch hub (18) rotates when the engine is running and air conditioning is switched on.

7

Close tailgate



Check condenser fans

Danger!

Risk of death due to falling off the vehicle roof Risk of injury to other persons due to objects falling down when working in the area of the roof

AS65.00-Z-0002-01A

8

Carry out visual inspection of condenser (arrows)

 The condenser fans (arrows) must operate when the air conditioning is switched on.



Check cooling capacity of the front box

9

Hold the sensor of the temperature measuring instrument in the air flow of the driver's 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 front box recirculated air flaps

10

Operate the recirculated air switch (3) for recirculated air mode

 The recirculated air flap must switch over audibly.



Check front box radial fans

11

Rotate the rotary switch for the driver area blower (2) from stage 1 to stage 2 and then to stage 3

 The blower capacity of the radial fan must noticeably increase significantly



Check front box heat output

12

Rotate the rotary controller for driver area temperature (4) to maximum heat output

13

Check the temperature of the air emerging in the driver area

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



*WH58.30-Z-1002-08A



Check passenger compartment air conditioning cooling capacity

14

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. Otherwise check the leaktightness of the air conditioning.





Checking air conditioning system for leakage

AR83.30-T-1209-01C



*WH58.30-Z-1002-08A



Check passenger compartment recirculated air flaps

15

Remove recirculating air filter for passenger compartment ventilation

AP83.10-T-8383BAS

16

Press recirculated air switch (3) for recirculated air mode and check the position of the air flaps (9)

 The air flaps (9) must be closed.

17

Check recirculated air switch (3) for recirculated air mode and check the position of the air flaps (9)

 The air flaps (9) must be open.



Check passenger compartment radial fans

18

Rotate the rotary switch for the passenger compartment blower (1) from stage 1 to stage 2 and then to stage 3

 The blower capacity of the radial fans must noticeably increase significantly.

19

Close all the open air nozzles (8) above the seats in the 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 flow on the left and right side of the vehicle

 If the power of the air flow emerging is not the same:



Check the function of the radial fan on the weak side and replace if necessary:





Remove/install radial fan

AR83.20-T-3750BA



Check radial fan for sleeping cab

22

Open the outer flap on the right of the sleeping cab

23

Rotate the rotary switch for the sleeping cab blower (15) in stages from stage 0 to stage 3

 The blower capacity of the radial fan must noticeably increase significantly



Check sleeping cab air conditioning cooling capacity

24

Rotate the rotary controller of cooling capacity (14) to maximum cooling capacity

25

Hold the sensor of the temperature measuring instrument in the air flow at the air nozzles (16) 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 sleeping cab air conditioning heat output

26

Rotate the rotary controller for cooling capacity (14) to minimum cooling capacity

27

Rotate regulating valve for heater (13) to maximum heat output

28

Check the temperature of the air emerging at the air nozzles (16)

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



*WH58.30-Z-1002-08A



Check passenger compartment air conditioning heater valve

29

Rotate rotary controller for passenger compartment temperature (7) to maximum heat output

30

Open right rear luggage compartment hatch

31

Check temperature at the heating pipes (12)

 The heating pipes (12) must heat up noticeably.



*WH58.30-Z-1002-08A

32

Close right rear luggage compartment hatch



Check passenger compartment air conditioning convectors

33

Check temperature at the convectors (10)

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



*WH58.30-Z-1002-08A

34

Switch off engine

35

Install recirculating air filter for passenger compartment ventilation

AP83.10-T-8383BAS

Number

Designation

WH58.30-Z-1002-08A

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