
DAEWOO M-150 BL2
SECTION 7A
HEATING AND VENTILATION SYSTEM
CAUTION: Disconnect the negative battery cable before removing or installing any electrical unit or when a
tool or equipment could easily come in contact with exposed electrical terminals. Disconnecting this cable
will help prevent personal injury and damage to the vehicle. The ignition must also be in B unless otherwise
noted.
TABLE OF CONTENTS
Description and Operation 7A-2. . . . . . . . . . . . . . . . . .
Heating and Ventilation Systems 7A-2. . . . . . . . . . . .
Component Locator 7A-3. . . . . . . . . . . . . . . . . . . . . . . .
Control Assembly 7A-3. . . . . . . . . . . . . . . . . . . . . . . . .
Blower Module Assembly 7A-4. . . . . . . . . . . . . . . . . . .
Air Distributor and Heater Module
Assembly 7A-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Diagnostic Informatin and Procedures 7A-6. . . . . . .
Heater System 7A-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Insufficient Heating or Defrosting 7A-6. . . . . . . . . . . .
Blower Electrical 7A-10. . . . . . . . . . . . . . . . . . . . . . . . .
Improper Air Delivery or No Mode Shift 7A-11. . . . . .
Too Much Heat 7A-13. . . . . . . . . . . . . . . . . . . . . . . . . . .
Controls 7A-15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Blower Noise 7A-16. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Repair Instructions 7A-18. . . . . . . . . . . . . . . . . . . . . . . .
On-Vehicle Service 7A-18. . . . . . . . . . . . . . . . . . . . . . . . .
Control Assembly and Control Cables 7A-18. . . . . . . Blower Motor and Cooling Hose 7A-20. . . . . . . . . . . .
Blower Resistor 7A-20. . . . . . . . . . . . . . . . . . . . . . . . . .
Blower Motor Switch 7A-21. . . . . . . . . . . . . . . . . . . . . .
Heater Hoses 7A-22. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Heater Module 7A-24. . . . . . . . . . . . . . . . . . . . . . . . . . .
Blower Module 7A-25. . . . . . . . . . . . . . . . . . . . . . . . . . .
Defroster Duct and Hoses 7A-26. . . . . . . . . . . . . . . . .
Ventilation Duct 7A-27. . . . . . . . . . . . . . . . . . . . . . . . . .
Unit Repair 7A-28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Heater Core 7A-28. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications 7A-29. . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Specifications 7A-29. . . . . . . . . . . . . . . . . . . .
Fastener Tightening Specifications 7A-29. . . . . . . . . .
Special Tools and Equipment 7A-30. . . . . . . . . . . . . .
Special Tools Table 7A-30. . . . . . . . . . . . . . . . . . . . . . .
Schematic and Routing Diagrams 7A-31. . . . . . . . . .
Non-A/C Diagrams 7A-31. . . . . . . . . . . . . . . . . . . . . . .
Air Flow Through Ducts (Non–A/C) 7A-32. . . . . . . . .

7A–4 HEATING AND VENTILATION SYSTEM
DAEWOO M-150 BL2
BLOWER MODULE ASSEMBLY
(Left–Hand Drive Shown, Right–Hand Drive Similar)
D18A402A
1. Blower Module Assembly
2. Plastic Washer
3. Blower Link
4. Blower Lever
5. Air Intake Case
6. Valve Retainer
7. Heater Duct Assembly
8. Blower Connector Duct9. Orifice Case
10. Cable Clamp
11. Blower Valve
12. Blower Resistor
13. Lower Case
14. Cooling Hose
15. Blower Motor

7A–6 HEATING AND VENTILATION SYSTEM
DAEWOO M-150 BL2
DIAGNOSTIC INFORMATION AND PROCEDURES
HEATER SYSTEM
INSUFFICIENT HEATING OR DEFROSTING
Caution: The cooling system is pressurized when hot. Injury can result from removing the surge tank cap
before the engine is sufficiently cool.
Step Action Value(s) Yes No
1
Verify the customer’s complaint.
Are the customer’s concerns verified?
–
Go to Step 2
System OK
2 Check the coolant level.
Is the coolant level correct? – Go to Step 4 Go to Step 3
3
Add coolant as needed.
Is the repair complete?
–
System OK
Go to Step 4
4
Check the timing belt for tension or damage.
Is the timing belt OK?
–
Go to Step 6
Go to Step 5
5
Correct any problem with the drive belts.
Is the repair complete?
–
System OK
Go to Step 6
6
Check the coolant hoses for leaks or kinks.
Are the coolant hoses OK?
–
Go to Step 8
Go to Step 7
7 Repair any problem with the coolant hoses.
Is the repair complete? –
System OK
Go to Step 8
8
Check the surge tank cap. Refer to Section 1D,
Engine Cooling.
Is the surge tank cap OK?
–
Go to Step 10
Go to Step 9
9
Repair or replace the surge tank cap as needed.
Is the repair complete?
–
System OK
Go to Step 10
10
1. Set the A/C switch OFF on vehicles equipped
with air conditioning.
2. Set the blower motor switch on 4.
3. Set the heater control to full hot.
4. Turn the ignition ON.
5. Check for airflow from the heater outlet.
Is there heavy airflow from the heater outlet?
–
Go to Step 11
Go to Step 25
11
Check for a change in the airflow at various blower
speeds.
Does the blower speed increase as the switch is
turned from 1 to 4?
–
Go to Step 12
Go to ‘‘Blower
Electrical’’
12
1. Set the A/C switch to OFF, on vehicles equipped
with air conditioning.
2. Set the temperature lever to full hot.
3. Set the blower motor switch on 4.
4. With the engine sufficiently cool, remove the
surge tank cap.
5. Start the vehicle and idle the engine.
6. Watch for the flow of the coolant.
Is the coolant flow visible?
–
Go to Step 14
Go to Step 13