2004 DAEWOO LACETTI heater

HEATING AND VENTILATION SYSTEM 7A – 13
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
151. Check for obstructions in the system at the
blower inlet and check the air filter if the vehicle
is so equipped.
2. Remove any obstructions at the blower inlet
and replace the filter if it is clogged.
Is the repair complete?–System OKGo to Step 16
161. Set the blower on 4.
2. Rotate the temperature control from full hot to
full cold.
3. Listen for an airflow change.
Does the airflow change?–Go to Step 17Go to Step 18
171. Check the temperature door, the cable, the
linkage, and the control.
2. Adjust the temperature control to full hot.
Is the repair complete?–System OK–
181. Check the system for any obstruction between
the blower and the system outlets.
2. Remove any obstruction between the blower
and the system outlets.
Is the repair complete?–System OK–
TOO MUCH HEAT
StepActionValue(s)YesNo
1Verify the customer’s complaint.
Are the customer’s concerns verified?–Go to Step 2System OK
2Is there too much heat when the mode switch is in
the floor position?–Go to Step 3Go to Step 9
3Is there objectionable defroster bleed?–Go to Step 4Go to Step 5
41. Check the door travel, the cable, the vacuum
actuators, and the linkage for the heater and
the defroster.
2. Adjust or repair, as required.
Is the repair complete?–System OK–
51. In vehicles equipped with A/C, set the A/C
switch OFF.
2. In all vehicles, set the blower speed to maxi-
mum.
3. Set the temperature to full hot.
4. Turn the ignition switch ON.
5. Check for airflow from the floor outlets.
6. Check the floor outlet attachment.
Is the airflow high?–Go to Step 6Go to Step 8
6Check for a change in the airflow at different blower
speeds.
Does the airflow change as the setting for the blow-
er–speed switch is scanned?–Go to Step 7 Go to ”Blower
Electrical
(Manual and
Non–A/C)”

7A – 18IHEATING AND VENTILATION SYSTEM
DAEWOO V–121 BL4
MAINTENANCE AND REPAIR
ON–VEHICLE SERVICE
TEMPERATURE CABLE
ADJUSTMENT
Because the cable and the cable housings have fixed
lengths, it is impossible to make a temperature cable ad-
justment.
In addition, the heater/air distributor case linkage cannot
be adjusted.
If a malfunction is suspected, verify the proper operation
of the controller and the mechanical doors for the heater/
air distributor case assembly.
TEMPERATURE CONTROL CABLE
(Left–Hand Drive Shown, Right–Hand Drive
Similar)
Removal Procedure
1. Disconnect the negative battery cable.
2. Remove the center molding. Refer toSection 9E,
Instrumentation/Driver Information.
3. Disconnect the mode control cable from the mode
door.
4. Disconnect the temperature control cable eyelet
from the post on the controller.
5. Pry off the clip of the temperature control cable.

HEATING AND VENTILATION SYSTEM 7A – 21
DAEWOO V–121 BL4
5. Gently insert the center molding into position on the
instrument panel.
6. Connect the negative battery cable.
7. Confirm the proper operation of the controller by
moving it through all of the controller’s possible
functioning positions.
CONTROL ASSEMBLY KNOB
LIGHTING
(Left–Hand Drive Shown, Right–Hand Drive Similar)
Removal Procedure
1. Disconnect the negative battery cable.
2. Remove the center molding. Refer to ”Control As-
sembly” in this section.
3. Turn the bulb holder to the left and pull out the bulb.
Installation Procedure
1. Install the bulb into the holder and turn the bulb to
the right.
2. Install the control assembly. Refer to ”Control As-
sembly” in this section.
3. Connect the negative battery cable.
4. Check the knob light for proper operation.
HEATER/AIR DISTRIBUTOR CASE
ASSEMBLY
Removal Procedure
1. Disconnect the negative battery cable.
2. Remove the instrument panel and tie–bar. Refer to
Section 9E, Instrumentation/Driver Information.
3. Drain the cooling system. Refer to Section 1D, En-
gine Cooling.
4. Compress the heater hose clamps at the firewall
and slide the clamps toward the engine.
5. Remove the two heater hoses from the core pipes
at the firewall.

7A – 22IHEATING AND VENTILATION SYSTEM
DAEWOO V–121 BL4
6. Remove the screws that secure the heater/air dis-
tributor case assembly to the firewall on the side of
the heater core pipes.
7. Remove the high–pressure and Low–pressure pipe
from the A/C expansion valve.
8. Remove the evaporator drain hose.
9. Have an assistant support the heater/air distributor
case from inside the vehicle.
10. Remove the screws that secure the heater/air dis-
tributor case assembly to the firewall on the side of
the evaporator.
11. Disconnect the rear duct connector.
Notice : Handle the case carefully to avoid damage to the
mechanical door operating linkage.
12. Remove the heater/air distributor case assembly
from the vehicle.
Installation Procedure
1. Position the heater/air distributor case assembly in
the vehicle.
Notice : Avoid damaging the heater core pipes by making
sure they do not contact the firewall opening.
2. Slowly raise the heater/air distributor case assem-
bly into position against the firewall and hold it in
position while the screws are installed and tight-
ened from the engine side of the firewall.
3. Install the high–pressure and low–pressure pipe.
4. Install the heater/air distributor case assembly
screws at the side of evaporator through the firewall
from the engine compartment side.

HEATING AND VENTILATION SYSTEM 7A – 23
DAEWOO V–121 BL4
Tighten
Tighten the heater/air distributor case assembly
screws to 4 NSm (35 lb–in).
5. Install the heater/air distributor case assembly
screws at the side of the heater core pipes through
the firewall from the engine compartment side.
Tighten
Tighten the heater/air distributor case assembly
screw to 4 NSm (35 lb–in).
6. Install the two heater hoses.
7. Slide the heater hose clamps into position.
8. Connect the rear duct connector.
9. Install the instrument panel and tie–bar. Refer to
Section 9E, Instrumentation/Driver Information.
10. Fill the cooling system. Refer to Section 1D, Engine
Cooling.
11. Connect the negative battery cable.
12. Operate the controls to verify the proper function of
the heating and ventilation systems.
BLOWER MOTOR
Removal Procedure
1. Disconnect the negative battery cable.
2. Remove the glove box. Refer to Section 9E, Instru-
mentation/Driver Information.
3. Put the floor carpet aside for preventing stain.
4. Disconnect the blower motor electrical connector
and resistor connector.
5. Remove the screws that secure the motor to the
heater/air distributor case.

7A – 24IHEATING AND VENTILATION SYSTEM
DAEWOO V–121 BL4
6. Remove the motor, the seal, and the shock mount
pads from the heater/air distributor case by gently
pulling the motor straight down and out.
Installation Procedure
1. Install the blower motor and the seal with the shock
mount pads in the heater/air distributor case. Hold
the blower motor in position.
2. Install the screws to secure the blower motor to the
heater/air distributor case.
Tighten
Tighten the blower motor retaining screws to 1.2 NSm
(11 lb–in).
3. Connect the blower motor electrical connector and
resistor connector.
4. Connect the negative battery cable.
5. Confirm that the blower motor operates properly.
6. Replace the glove box. Refer to Section 9E, Instru-
mentation/Driver Information.
HIGH–BLOWER RELAY
Removal Procedure
1. Disconnect the negative battery cable.
2. Remove the glove box housing. Refer to Section
9E, Instrumentation/Driver Information.
3. Separate the connector from the bracket.
4. Disconnect the relay from the connector.
Installation Procedure
1. Connect the relay to the connector.
2. Insert the connector to the bracket.
3. Install the glove box. Refer to Section 9E, Instru-
mentation/Driver Information.

HEATING AND VENTILATION SYSTEM 7A – 25
DAEWOO V–121 BL4
BLOWER RESISTOR
Removal Procedure
1. Disconnect the negative battery cable.
2. Remove the glove box. Refer to Section 9E, Instru-
mentation/Driver Information.
3. Disconnect the electrical connector at the resistor.
4. Remove the mount screws from the resistor.
5. Remove the resistor from the heater/air distributor
case by gently pulling the resistor downward.
Installation Procedure
1. Install the resistor into the heater/air distributor
case with the screws.
Tighten
Tighten the blower motor resistor screws to 1.2 NSm
(11 lb–in).
2. Connect the electrical connector at the resistor.
3. Connect the negative battery cable.
4. Confirm the proper performance of the blower.
5. Replace the glove box. Refer to Section 9E, Instru-
mentation/Driver Information.
HEATER HOSES
Removal Procedure
1. Partially drain the cooling system.
2. Raise and suitably support the vehicle.
3. Compress and slide rearward the two heater hose
spring clamps at the firewall.
4. Gently twist the hose from the left to the right and
back again to loosen the bond between the hose
and the tube.
5. Remove the end of the hose from the tube.
6. Repeat Steps 3 and 4 with the other hose.
7. Compress the heater hose spring clamp on the inlet
coolant line and slide the clamp rearward.
8. Remove the inlet heater hose from the vehicle.
9. Compress the heater hose spring clamp on the out-
let coolant line and slide the clamp backward.
10. Remove the outlet heater hose from the vehicle.

7A – 26IHEATING AND VENTILATION SYSTEM
DAEWOO V–121 BL4
Installation Procedure
1. Install the left heater hose to the coolant inlet line
fitting. Slide the end of the heater hose over the
coolant fitting until the hose is seated.
2. Install the right heater hose to the fitting below the
intake manifold. Slide the end of the heater hose
over the fitting until it is seated.
3. Install and seat the other end of each heater hose.
4. Compress and slide the spring clamps into position
on the heater hoses and release the tension.
5. Fill the cooling system.
6. Check the hoses for leaks.
7. Lower the vehicle.
HEATER CORE
(Left–Hand Shown, Right–Hand Drive Similar)
Removal Procedure
1. Disconnect the negative battery cable.
2. Remove the instrument panel. Refer to Section 9E,
Instrumentation/Drive Information.
3. Recover the refrigerant.
4. Remove the heater/air distributor case assembly.
Refer to ”Heater/air distributor case assembly” in
this section.
5. Remove the wiring harness and electrical connec-
tors from the heater/air distributor case assembly.
6. Remove the screws that connect the heater core
housing and the evaporator housing.
7. Separate the sponge from heater/air distributor
case assembly.
8. Remove the heater core cover screws from the
heater core housing.
9. Remove the heater core.