Webasto Air Top 2000 ST D Service And Repair Manual page 24

CIRCUIT DIAGRAMS
BATTERY
X9
S1
3
0,5mm2 rt
4
0,5mm2
sw
H1
1
0,5mm2 bl
2
0,5mm2 ws
GROUND
Diagnostic K cable
1
W bus
2
CO setting
3
2
Input pin (pin 16/plug X6), cable color on wiring harness: pink):
4
"Ventilation" (fan speed depends on the position of the control element)
If you use an external temperature sensor (B4), the resistor (R1) is replaced by the temperature sensor (B4).
5
6
NOTE - Typical Connection for Trucks
If this connection is made to battery positive (terminal 30), permanent heating is possible with the
ignition switched off. In this case no connection must be made to terminal 15/75.
NOTE - Typical Connection for Buses
7
With positive from terminal (15/75) to connection 10:
Permanent operation for immediate heat as long as the ignition is switched on.
Without positive at connection 10:
Heating time is variably programmable (10 min to 120 min), default setting 120 min.
Item Designation
A1 Heater
A2 Control unit
B1 Flame sensor
B2 Temperature sensor
B3 Overheating sensor
B4 Temperature sensor
E Ceramic glow pin
F1 Fuse 15A (max. 20A)
F2 Fuse max. 15 A
H1 LED, green (in item S1) Indicator
H3 LED, red
H4 Heating symbol in the
display (in item P)
H5 Light (in item P)
M1 Motor
P Combination timer
(1531)
Figure 12: System Circuit Diagram 12V/24V with Control Element (Rheostat Switch)
Webasto Product N.A., Inc.
F1
X6
1
13
12
10
11
2
1 2 3
1 2
br br ge ge br
X2
12V rt
X1
24V gn
M
M1
E
A1
X8
X8
Comment
Air Top 2000 ST
Gasoline heaters only
Internal
Overheating guard
External
Flat fuse SAE J 1284
Flat fuse SAE J 1284
Immediate heat button light
Ready indicator, switch-on indicator
Indicator
Display and button lights
Combustion and hot air fan
Timer and temperature control
3 2
S6
1 2
X11
1
14 15
7 5 6
A2
B2
1 2
2 1 9 8 2 1
bl
bl
br X6 X4 X3
X5
B1 B3
2
1
X10
R1
2
1
5
Y1
B4
Item Designation
Resistor 620 Ω
R1
S1 Control element
S4 Switch (optional)
S6 Switch
X1 Plug connector, 4-pin
X2 Plug connector, 2-pin
X3 Plug connector, 2-pin
X4 Plug connector, 2-pin
X5 Plug connector, 2-pin
X6 Plug connector, 18-pin to item A2
X8 Plug connector, 2-pin
X9 Plug connector, 4-pin
X10 Plug connector, 2-pin
X11 Plug connector, 2-pin
X12 Plug connector, 12-pin to item P
Y1 Fuel metering pump
24
AIR TOP 2000 ST
30
4
3
16
4
17
X6
4
3
S3
Cable Cross-sections
< 7.5 m 7.5 – 15 m
2
2
0.75 mm 1.0 mm
2
2
1.0 mm
0.75 mm
2
2
1.5 mm
1.0 mm
2
2
2.5 mm
1.5 mm
2 2
4.0 mm
2.5 mm
2
2
4.0 mm 6.0 mm
Standard cable
Comment
With internal temperature sensor
only
Switch and temperature control
Ventilation
CO setting
2
to item A2
to item A2
to item A2
to item A2
to item A2
to item S1
to item Y1
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X1
X2/X3/X4/X5
2
1
X6
X8
2
1
X9
1
2
X10
1 2
1 2
X11
2
1
Cable Colors
bl Blue
br Brown
ge Yellow
gn Green
gr Grey
or Orange
rt Red
sw Black
vi Violet
ws White