7 Circuit diagrams Thermo 90 S / Thermo 90 ST
704
Fig. 703 System circuit for Thermo 90 S-ADR, 24 V, with switch
Temperature coding (temperature at water outlet):
See table on page 302
Vehicle fuse
Vehicle fan switch
1
3
4
A
F
E
B
30
85
86 87
87a
H2
S4
K5
br
br
br
rt
br
gn/ws
rt/bl
ge
sw
rt
ws/bl
vi
bl
vi/bl
gr
gn
or
or
58
15
12
D+/61
58
15
D+/61
F2 F3
X6
S7
F1
bl
br
30
31
S5
S5
sw
rt
rt
ws
A2
11 6
12
2
2
2
3
1
0
710
32
1
1
1
4
58
11
9
9
4
3
71568212
M2
M3
M1
br
br
bl
239
8657
112
11 10 4
sw
br
X1
H5 Y2
Y1
vi
gr
gn
B3
B4
B1 B2
A1
E
M
M
M
ϑϑ
ge
B1
B3
B2
E
X1
M1
M2
sw
10
X12 (ST 2)
X5
X13
(ST 3)
X11
(ST 1)
vi
gr
gn
X5
X6
X13 (ST 3)
1
12
2
11
3
10
4
9
5
8
6
7
X1
1
1
2
2
X11 (ST 1) X12 (ST 2)
21
1
11
3
9
5
7
1
11
3
9
5
7
1
2
1
3
4
Cable cross-sections
< 7.5 m
7.5 - 15 m
0.75
mm
2
1.5 mm
2
2.5 mm
2
4.0 mm
2
1.5 mm
2
2.5 mm
2
4.0 mm
6.0 mm
1.0 mm
2
1.0 mm
2
1.0 mm
2
0.75 mm
2
2
2
Cable colours
bl
br
ge
gn
gr
or
rt
sw
vi
ws
Blue
Brown
Yellow
Green
Grey
Orange
Red
Black
Violet
White
Item Designation Comment
A1 Heater
A2 Control unit
B1 Flame monitor
B2 Temperature sensor
B3 Temperature limiter/
overheating guard circuit
B4 Cabin thermostat
E Glow plug
F1 20 A fuse Blade-type fuse SAE J 1284
F2 5 A fuse Blade-type fuse SAE J 1284
F3 20 A fuse Blade-type fuse SAE J 1284
H2 Light max. 2 W Operating indicator (in item S4)
H5 Lamp min. 1.2 W Switch-on indicator pumping device
K5 Relay For vehicle fan
M1 Motor Combustion air fan
M2 Motor Circulating pump
M3 Motor Vehicle fan
S4 Switch ON/OFF
Item Designation Comment
S5 1 or 2-pin disconnecting switch Emergency off switch
electrical or pneumatic
S7 Pumping device switch To positive
X1 12-pin plug connector To item A1
X5 12-pin plug connector To Y1
X6 12-pin plug connector Diagnosis
X11 12-pin plug connector To item A2 (ST 1)
X12 12-pin plug connector To item A2 (ST 2)
X13 12-pin plug connector To item A2 (ST 3)
Y1 Metering pump Fuel pump for heater
Y2 Solenoid valve For pumping device
