Heater and ventilation, heater booster - function check

AP83.00-T-8351B

Heater and ventilation, heater booster - function check

2.11.98



Check

1

Make sure that the shut-off valves in the hot water feed and return lines are open

See owner's manual

 Danger!

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

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

2

Start engine

 A minimum coolant temperature of
50 °C must be ensured. Switch on auxiliary heater if necessary.



Check ventilation in front compartment of vehicle

3

Set switch gradually for front area ventilation up to highest blower output

See owner's manual

 The blower output at the air outlets on the driver area must increase significantly.

4

Set temperature selector for front area to highest heat output

See owner's manual

5

Measure temperature of air exiting at air outlets

 Hot air must exit at the air outlets.



*WH58.30-Z-1002-08A

6

Check air distribution to the heating and ventilation nozzles.

 To do this, turn rotary switch (2) through all settings.

Guide air flow for front compartment ventilation up to windshield and down to footwell using rotary switch (2).



Check blower automatic cutoff

7

Operate switch for passenger compartment ventilation

 See Operating Instructions

8

Open and close the passenger doors using the passenger door buttons (1) one after the other and check the blowers for proper operation

 The blowers must switch off automatically when the passenger doors are open.

9

Switch off blowers for front compartment.

See owner's manual

10

Set temperature selector for front area to lowest heat output

See owner's manual



Check ventilation for passenger compartment.

11

Set temperature selector for passenger compartment to highest heat output

See owner's manual

12

Set blower for passenger compartment ventilation to highest blower output

See owner's manual

 The blower capacity in the passenger compartment must increase significantly.

13

Close all the open air nozzles (19) above the seats in the passenger compartment

14

Open one air nozzle (19) on the left and right side of the vehicle

15

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

 If the force of the exiting air is not equal, then check the relevant radial fans for correct operation.

16

Measure temperature of air exiting at air outlets (19)

 Hot air must exit at the air outlets (19).



*WH58.30-Z-1002-08A



Check convectors in passenger compartment

17

Measure temperature at convectors (21)



*WH58.30-Z-1002-08A

18

Switch off blowers for passenger compartment ventilation.

 See Operating Instructions

19

Set temperature selector for passenger compartment to lowest heat output

 See Operating Instructions



Check fresh air/recirculated air flaps in passenger compartment

20

Move air flap switch to "passenger compartment recirculated air" position.

 See Operating Instructions

The air flaps (20) must be set to the recirculated air position, for test purposes the grille in front of the air flaps (2) may have to be removed.

21

Move air flap switch to "fresh air" position.

 See Operating Instructions

The air flaps (20) must be set to the fresh air position.



Check recirculated air flaps for front area ventilation

22

Switch blower switch for front compartment ventilation to highest setting.

 See Operating Instructions

23

Move air flap switch to "front compartment recirculated air" position.

 See Operating Instructions

The recirculated entry at the grille (3) must be clearly felt with the hand.

24

Move air flap switch to "fresh air" position.

 See Operating Instructions

No recirculated air at the grille (3).

25

Switch off blower switch for front compartment.

26

Check auxiliary heater

AP83.00-T-8351-01A

27

Turn off engine

Number

Designation

WH58.30-Z-1002-08A

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