Webasto Thermo 50 Installation Instructions Manual page 49

Circuit diagrams
Item Designation
A1 Heater
A2 Control unit
B2 Temperature sensor
E Glow plug / flame monitor
F1 Fuse 15 A
F2 Fuse 5 A
F3 Fuse
H1 LED (in item P)
H2 LED (in item P)
H3 Light (in item P)
H4 Light
H5 Light min. 1.2 W
K2 Relay
K3 Relay (in item A3)
M1 Motor
M2 Motor
M3 Motor
P Timer, digital
S1 Switch for vehicle fan
S2 Switch for vehicle fan
S3 Switch
S4 1 or 2-pin
disconnecting switch
S5 Switch
S6 Switch
S7 Momentary-contact switch Immediate heat button /
X1 6-pin plug connection
X2 2-pin plug connection
X3 2-pin plug connection
X4 2-pin plug connection
X5 2-pin plug connection
46
Comment
Thermo 50
Flat fuse SAE J 1284
Flat fuse SAE J 1284
Fuse same as vehicle fan fuse
(max. 20 A)
Switch-on indicator
Indicator
Display light
Indicator
Switch-on indicator pumping device
For pumping device
Vehicle fan
Combustion air fan
Circulation pump
Vehicle fan
For programmed operation
S1 or S2 depending on vehicle
S1 or S2 depending on vehicle
Immediate heat button
Emergency off switch,
electr. or pneumatic
To pumping device 1
To pumping device 2
remote control
Item Designation
X6 2-pin plug connection
X8 2-pin plug connection
X11 2-pin plug connection
X12 12-pin plug connection
X13 1-pin plug connection
X14 1-pin plug connection
X15 4-pin plug connection
Y1 Metering pump
Y2 Solenoid valve
Y3 Solenoid valve
Thermo 50
Comment
Diagnostics
Timer
Battery isolation switch
Auxiliary power take-off
On / off switch
for pumping device 1
for pumping device 2