Technical data

Repair Air Top 2000 ST
904
9.2.3 Replace control unit
9.2.3.1 Removal
1. Remove heater (see 8.7.1.1).
2. Remove casing parts (see 9.2.1).
3. Spread apart the lock of the hot air blower.
4. Pull the hot air blower (1, Fig. 903) off the motor shaft
by hand.
5. Disconnect plug connections on control unit (3).
6. Remove screws (2) and control unit (3).
7. Complete work on stripped down components (see
9.1.1).
NOTE
Do not carry out any repair work to the control unit.
9.2.3.2 Installation
1. Move control unit (3, Fig. 903) into installation position
and tighten screws (2).
2. Tighten screws to 0.7 ± 0.07 Nm..
3. Slide hot air blower (1) onto motor shaft up to stop. Lug
on both sides can be heard to engage in shaft groove.
4. Produce plug-in connections on socket outlets of con-
trol unit (3) as shown in Fig. 701.
5. Lay on casing parts (see 9.2.2).
6. Install heater (see 8.7.1.2)
7. Check the CO
2
setting and adjust if necessary (see 6.3).
8. Check smooth running of the hot air blower by hand
and listen for any noises when switching on later.
Sensor magnets on the hot air blower must be free of
chips containing iron etc.
9.2.4 Change overheating sensor
9.2.4.1 Removal
1. Remove heater (see 8.7.1.1).
2. Remove casing parts (see 9.2.1).
3. Remove insulators (9, Fig. 903).
4. Disconnect plug connection X5 on control unit (3).
IMPORTANT
Do not pull the cables.
5. Lever overheating sensor (8) out of heat exchanger’s
ribs (7) using a suitable tool (see Detail A).
6. Remove overheating sensor (8).
9.2.4.2 Installation
1. Conduct resistance measurement on overheating sen-
sor (8, Fig. 903) (see 6.4.5).
2. Position overheating sensor (8) on heat exchanger (7)
and press it into place by hand.
IMPORTANT
No electrical connection may exist between the sensor
wires and the sheet-metal bracket.
3. Ensure that overheating sensor is correctly positioned in
heat exchanger (7).
4. Connect plug connection X5 to the control unit (3).
Ensure parallel routing of the cable duct between the
ribs of the heat exchanger.
5. Slide insulators (9) onto heat exchanger.
6. Lay on casing parts (see 9.2.2).
7. Install heater (see 8.7.1.2)
9.2.5 Replacing combustion air fan
9.2.5.1 Removal
1. Remove the heater (see 8.7.1.1).
2. Remove the casing parts (see 9.2.1).
3. Remove the control unit (see 9.2.3.1).
NOTE
A total of 9 screw heads are visible on the combustion air
fan (5, Fig. 903). Of those the outer 5 screws are used to fas-
ten the combustion air fan on the heat exchanger (7). Only
these screws are to be removed.
4. Remove the screws (4).
5. Pull the combustion air fan (5) off the heat exchanger
(7), remove the seal (6) and dispose of it separately.
6. Complete the work on stripped down components (see
9.1.1).
9.2.5.2 Installation
1. Make sure that sealing surfaces on combustion air fan
(5, Fig. 903) and heat exchanger (7) are not damaged.
2. Place the new seal (6) on the flange of the combustion
air fan (5).
3. Move the combustion air fan (5) into the assembly posi-
tion and fasten with the screws (4) while also fastening
the earth connection of the wiring harness on the en-
gine.
4. Tighten the screws (4) to 6 ± 0.6 Nm.
5. Install the control unit (see 9.2.3.2).
6. Lay on the casing parts (see 9.2.2).
7. Install the heater (see 8.7.1.2)
8. Check the CO
2
setting and adjust if necessary
(see 6.3).