or responsible for its content.
Installation Instructions
Page 1 of 5
Rev. 12/00 907607B
www.webasto.com
Installation / Wiring Modification Instructions for Sleeper Pak P.N. 906543.
Associated Products - Thermo 90 S & DBW 2010.73
For Use On the Following Vehicles:
Freightliner - Century Class, Classic, FLD
Kenworth - Modular Sleeper Box, T2000
Kenworth - AeroCab & Studio Sleeper built before September 1996
Mack - CL, CH, Vision
Peterbilt - Model 387
Sterling Truck with Sleeper Unit (all)
Western Star - All Models
Volvo VN - fan speed controlled through positive side wiring (ending 1995 inclusive)
Volvo VN - fan speed controlled through negative side wiring (year starting 1996)
Volvo WIA
Kit Contents:
Thermostat - P.N. 70947A
Wiring Harness - P.N. 905614B
Installation Instructions
1. Install the Webasto thermostat. Locate the thermostat in an area where the routing of the
wiring is possible, about half way between the ceiling and bed. Do not locate in the direct
airflow from the heat exchanger. The bunk control panel is usually the preferred location.
2. Mount interlock relay near the heat exchanger.
3. Route the blower interlock harness (with 3-pin Deutsch connector) to the Webasto heater.
Route the thermostat harness from the interlock relay at the heat exchanger to the
thermostat and secure every 12 inches.
4. Make the wiring connections at the thermostat and heater unit per wiring schematics
shown on page 2, 3 or 4 depending on truck make and model.
5. Plug the Deutsch connector into the Deutsch receptacle located in the Webasto heater
enclosure.
6. Insert a 10 Amp. fuse into the fuse holder located in the Webasto heater enclosure.
Sleeper Pak P.N. 906543
For questions concerning these installation instructions or products detailed on this sheet, call:
1-800-555-4518 USA
1-800-667-8900 Canada
Installation Instructions Page 2
of 5
Rev
. 12/00 907607B
www
.webasto.com
87
87a
85
86
30
Heat Exchanger
Fan Motor Unit
Relay Socket
Resistor
Pack
C
B
A
Existing Power Source
to Bunk Heater
Blower Speed
Select Switch
Webasto Thermostat
with On/Off Switch
P.N. 70947A
White
Power
Negative
Heater On
Signal
Green
Green
Black
Black
High
Medium
Low
85
86
87
30
87a
White
White
Violet
Butt Splice
Butt Splice
3-way
Connector
General Wiring Connections with Interlock Harness P.N. 905614B
Use with all vehicles listed EXCEPT:
Volvo VN with fan speed controlled through negative side wiring (year starting 1996)
and Sterling Trucks (all)
Installation Instructions
5
4
2
For questions concerning these installation instructions or products detailed on this sheet, call:
1-800-555-4518 USA
1-800-667-8900 Canada
Sleeper Pak P
.N. 906543 Sleeper Pak P.N. 906543
For questions concerning these installation instructions or products detailed on this sheet, call:
1-800-555-4518 USA
1-800-667-8900 Canada
Installation Instructions
Page 3 of 5
Rev. 12/00 907607B
www.webasto.com
Interface Section to Existing Wiring
(See close-up, lower left of page)
Connections with Interlock Harness P
.N. 905614B
V
olvo VN with fan speed controlled through
negative side wiring (year starting 1996)
W
ebasto Drawing Number 908231A Sleeper Pak P.N. 906543
For questions concerning these installation instructions or products detailed on this sheet, call:
1-800-555-4518 USA
1-800-667-8900 Canada
Installation Instructions
Page 4 of 5
Rev. 12/00 907607B
www.webasto.com
Connections with Interlock Harness P
.N. 905614B
Sterling T
ruck with Sleeper Unit (all).
Sterling Drawing Number DO6-29714-000
W
ebasto Drawing Number 908210 Rev
. 12/00 Page 5 of 5
Rev. 12/00 907607B
www.webasto.com
Installation Instructions
Final System Checks for Proper Operation
When the Webasto heater is switched on and the thermostat is set to a temperature higher
than ambient temperature in the bunk, the bunk blower motor should operate at medium low
speed. Turning the thermostat dial to a lower setting than the ambient temperature in the
bunk should turn the bunk blower motor off.
IMPORTANT! Do not set fan speed control above medium speed on the Volvo VN with fan
speed controlled through negative side wiring (year starting 1996). The 10 amp. interlock
system fuse located in the Webasto heater enclosure will respond as a result.
DO NOT increase fuse rating! It is not recommended that the heating system be operated on
high speed due to increased battery draw and subsequent reduction in operating time.
NOTE: On all other vehicles listed, the blower motor speed selector on the bunk control
panel must be set to "OFF" during Webasto heater operation. When the Webasto heater
is switched off, operation of all bunk blower motor functions should resume normal OEM
system control.
Operation
With the engine off and the Webasto heater on.
Switching the thermostat on and setting the thermostat dial to a point higher than the ambient
temperature in the bunk will energize a relay which will then switch power to the fan allowing
it to operate. When ever the Webasto heater system is not in use, (thermostat switch OFF)
the OEM heating system will operate in the standard mode as before modification.
Fan Speed Selection
Volvo VN with fan speed controlled through negative side wiring (year starting 1996).
Set the fan speed select switch on the sleeper control panel to low or medium speed when-
ever the Webasto heater and thermostat are in use. DO NOT use high speed setting! The
10 amp. interlock system fuse located in the Webasto heater enclosure will respond as a
result.
When the Webasto heater is switched off, operation of all bunk blower motor functions will
resume normal OEM system control.
All other truck make and models listed.
The blower motor speed selector on the bunk control panel must be set to "OFF" during
Webasto heater operation.
When the Webasto heater is switched off, operation of all bunk blower motor functions will
resume normal OEM system control.
For questions concerning these installation instructions or products detailed on this sheet, call:
1-800-555-4518 USA
1-800-667-8900 Canada
Sleeper Pak P.N. 906543
Installation Instructions