speed DAEWOO LACETTI 2004 Service Repair Manual

HEATING AND VENTILATION SYSTEM 7A – 9
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
341. Set the blower on maximum speed.
2. Rotate the temperature control from full hot to
full cold.
3. Listen for an airflow change.
Does the airflow change?–Go to Step 35Go to Step 36
351. Check the following aspects of the temperature
door:
S Travel.
S Cables.
S Linkage.
S Control.
2. Verify the accuracy of the temperature control
at full hot.
Is the repair complete?–Go to Step 1–
361. Check the system for any obstruction between
the blower and the system outlets.
2. Remove any obstruction.
Is the repair complete?–Go to Step 1–
BLOWER ELECTRICAL
StepActionValue(s)YesNo
1Verify the customer’s complaint.
Are the customer’s concerns verified?–Go to Step 2System OK
2Turn the blower ON.
Does the blower run at any speed?–Go to Step 14Go to Step 3
31. Disconnect the power connector from the blow-
er motor under the dashboard on the passen-
ger side of the vehicle.
2. Turn the ignition ON.
3. Turn the blower ON.
4. Test for voltage on the connector. The terminal
connected to the violet wire is positive and the
terminal connected to the black wire is nega-
tive.
Is this voltage present?11–14vGo to Step 4Go to Step 5
4Replace the blower motor.
Is the repair complete?–System OK–
5Check fuse F7 in the I/P fuse block in the engine fuse
block.
Is the fuse blown?–Go to Step 6Go to Step 7
61. Turn the ignition ON.
2. Use a short detector to locate a possible short
in the following locations:
S Fuse panel–to–blower speed switch.
S Blower speed switch–to–heater resistor
block.
S Heater resistor block–to–blower motor.
S Blower speed switch–to–blower HI relay.
3. Repair any short.
4. Replace any blown fuse.
Is the repair complete?–System OK–

7A – 10IHEATING AND VENTILATION SYSTEM
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
71. Turn the ignition ON.
2. Set the blower switch on 4.
3. Check the blower motor ground.
Is ground OK?–Go to Step 9Go to Step 8
8Repair the blower motor ground.
Is the repair complete?–System OK–
9Check the motor connector with a 12–volt test light.
Does the test light come on?–Go to Step 10Go to Step 11
10Repair the open in the feed wire from the resistor
block to the blower motor.
Is the repair complete?–System OK–
11Use the 12–volt test light to check the power feed
terminal on the blower speed switch.
Does the light come on?–Go to Step 12Go to Step 13
12Replace the blower speed switch.
Is the repair complete?–System OK–
13Repair the open in the power wire from the blower
speed switch to the fuse panel.
Is the repair complete?–System OK–
14Turn the blower on speed 4.
Does the blower fail to operate at speed 4?–Go to Step 15Go to Step 21
15Check fuse EF3 in the engine fuse block.
Is the fuse blown?–Go to Step 16Go to Step 17
161. Turn the ignition ON.
2. Turn the blower motor switch to 4.
3. Use a short detector to locate a possible short
in the following locations:
S Engine fuse panel–to–blower HI relay.
S Blower HI relay–to–blower motor.
4. Repair any short.
5. Replace the EF3 fuse.
Is the repair complete?–System OK–
171. Turn the ignition switch ON.
2. Set the blower switch to 4.
3. Check for 12 volts on the blower HI relay coil
terminal from the blower speed switch terminal
A7.
Is this voltage present?–Go to Step 18Go to Step 19
18Replace the blower speed switch.
Is the repair complete?–System OK–
191. Turn the ignition OFF.
2. Check for opens in the following locations:
S EF3 fuse–to–blower HI relay.
S Blower speed switch–to–blower– HI relay.
S Blower HI relay–to–ground.
S Blower HI relay–to–blower motor.
3. Repair any opens.
Is the repair complete?–System OKGo to Step 20
20Replace the blower HI relay.
Is the repair complete?–System OK–

HEATING AND VENTILATION SYSTEM 7A – 11
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
211. Disconnect the resistor block connector.
2. Connect one lead of a self–powered test light
to any single lead on the resistor block. Use
the other lead to probe each of the other two
terminals.
Does the test light illuminate on all terminals?–Go to Step 23Go to Step 22
22Replace the resistor block.
Is the repair complete?–System OK–
231. Turn the ignition to LOCK.
2. Disconnect the connector from the resistor
block.
3. Connect a jumper lead from the positive termi-
nal on the battery to any wire terminal in the
connector.
4. Use a 12–volt test light to check for voltage
from the corresponding wire on the blower
speed switch.
5. Repeat the same test on the other wires.
Does the lamp light on all three wires?–Go to Step 25Go to Step 24
24Replace the blower speed switch.
Is the repair complete?–System OK–
25Repair the open in the affected wire.
Is the repair complete?–System OK–
IMPROPER AIR DELIVERY OR NO MODE SHIFT
This procedure provides a test of all functions of the heater/defroster unit.
1. Warm up the vehicle.
2. Keep the engine running.
3. Perform the tests outlined in the table below and look for the results indicated.
CONTROL SETTINGS
CORRECT RESULTS
Mode
KnobTe m p
Contro
lBlower
Motor
SwitchBlower
SpeedPower
Vent
OutletFloor
OutletDefrost
OutletSide
Window
Outlet
VentColdOffOffNo
AirflowNo
AirflowNo
AirflowNo
Airflow
VentCold4HighAmbient
AirflowNo
AirflowNo
AirflowNo
Airflow
FloorCold to
Hot4HighNo
AirflowCold to Hot
AirflowMinimum
Cold to Hot
AirflowMinimum
Cold to Hot
Airflow
De-
frosterCold to
Hot4HighNo
AirflowMinimum
Cold to Hot
AirflowCold to Hot
AirflowMinimum
Cold to Hot
Airflow
If any of these settings does not produce the correct results, perform the following diagnostic procedure.

7A – 12IHEATING AND VENTILATION SYSTEM
DAEWOO V–121 BL4
StepActionValue(s)YesNo
1Verify the customer’s complaint.
Are the customer’s concerns verified?Go to Step 2System OK
2S Examine the affected door in the unit for proper
attachment to the vacuum actuator.
S Check the actuator connection to the door.
S Check that the vacuum hose is properly con-
nected.
Is everything connected properly?–Go to Step 4Go to Step 3
3Repair as necessary.
Is the repair complete?–System OK–
41. Disconnect the actuator at the door.
2. Check the range of the door travel and the ef-
fort required to move it.
Does the door move freely through its entire range
of travel so that it can close at both ends of the
range?–Go to Step 5Go to Step 3
5Check the travel of the actuator by turning the con-
trol knob with the engine running.
Is the actuator travel OK?–Go to Step 6Go to Step 7
61. Reinstall the actuator.
2. Recheck the system using the ”Control Set-
tings/Correct Results” tests in this procedure.
Does the system perform properly?–System OKGo to Step 9
71. Check the vacuum hose at the control.
2. Check for a broken control.
Is there a problem with the vacuum hose or the con-
trol?–Go to Step 8Go to Step 9
8Repair the vacuum hose or the control as necessary.
Is the repair complete?–System OKGo to Step 9
9Recheck the system using the ”Control Settings/
Correct Results” tests in this procedure.
Is the repair complete?–System OKGo to Step 10
10Check for airflow from the defroster or the vent out-
lets.
Is there high airflow from the defroster or the vent
outlets?–Go to Step 11Go to Step 12
11Adjust the heater door at the floor and the vent door
to get the proper airflow.
Is the repair complete?–System OK–
12Switch the mode knob to defrost.
Is the defroster airflow OK?–Go to Step 13Go to Step 14
131. Remove the heater outlet.
2. Check the heater outlet for obstructions.
3. Remove any obstructions in the heater outlet.
Is the repair complete?–System OK–
14Check the blower speeds for change in the airflow.
Does the blower speed increase as the control is
turned from 1 to 4?–Go to Step 15Go to ”Blower
Electrical
(Manual and
Non–A/C)”

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 – 16IHEATING AND VENTILATION SYSTEM
DAEWOO V–121 BL4
BLOWER NOISE
StepActionValue(s)YesNo
1Verify the customer’s complaint.
Are the customer’s concerns verified?–Go to Step 2System OK
21. Sit inside the vehicle.
2. Close the doors and the windows.
3. Turn the ignition ON.
4. Start the engine.
5. Set the temperature to full cold.
6. Cycle through the blower speeds, the modes,
and the temperature settings in order to find
the noise.
Is the blower noise constant at high blower speeds
or certain modes, but absent at lower speeds or in
other modes?–Go to Step 11Go to Step 3
3Check for vibrations from the blower motor and fan
assembly at each blower speed by feeling the blower
motor housing.
Did you find excessive vibration?–Go to Step 6Go to Step 4
41. Remove the blower motor and the fan assem-
bly. Refer to ”Blower Motor” in this section.
2. Check for foreign material at the opening of the
blower inlet.
Do you find any foreign material at the blower inlet?–Go to Step 5Go to Step 6
5Remove all foreign material.
Is the repair complete?–System OKGo to Step 6
61. Examine the blower fan for wear spots,
cracked blades, a cracked hub, a loose fan re-
taining nut, or bad alignment.
2. Examine the blower case for wear spots.
Did you find any problem?–Go to Step 7Go to Step 9
7Repair as required.
Is the repair complete?–System OKGo to Step 8
8Replace the motor and the fan assembly.
Is the repair complete?–System OKGo to Step 9
9If the noise is a click/tick or whine, replace the motor.
Is the repair complete?–System OKGo to Step 10
10Reinstall the original motor.
Is the problem still present?–Go to Step 11System OK
111. Set the blower speed on maximum.
2. Check full–hot to full–cold temperature posi-
tions in the defrost, floor, and vent modes.
Is the noise present in the defrost mode only?–Go to Step 12Go to Step 13
121. Check the ducts for obstructions or foreign ma-
terials.
2. Remove any obstructions or foreign materials.
3. Check the floor/defroster door seals.
4. Repair or replace the components, as needed.
Is the repair complete?–System OK–
13Is the noise present in the floor mode only?–Go to Step 12Go to Step 14
14Is the noise present in the vent mode only?–Go to Step 15Go to Step 16

7A – 28IHEATING AND VENTILATION SYSTEM
DAEWOO V–121 BL4
GENERAL DESCRIPTION
AND SYSTEM OPERATION
HEATING AND VENTILATION
SYSTEMS
The base heater system is designed to provide heating,
ventilation, windshield defrosting, side window defogging,
and on some vehicles, heating directly to the rear seat
area.
The heater and fan assembly blower regulates the airflow
from the air inlet for further processing and distribution.
The heater core transfers the heat from the engine coolant
to the inlet air.
The temperature door regulates the amount of the air that
passes through the heater core. The temperature door
also controls the temperature of the air by controlling the
mix of the heated air and the ambient air.
The mode door regulates the flow and the distribution of
the processed air to the heater ducts and to the defroster
ducts.
This console–mounted heating and ventilation panel con-
tains the following:
The Rotary Temperature Control Knob
1. The Rotary Temperature Control Knob
S Actuates by cable.
S Raises the temperature of the air entering the
vehicle by rotation toward the right, or the red
portion of the knob.
2. The Rotary Blower Control Knob
S Turns ON to operate the blower motor at four
speeds.
S Turns OFF to stop the blower.
S Operates completely independently both from
the mode control that regulates the defroster
door and from the temperature control knob.S Changes the fan speed in any mode and at any
temperature setting.
3. The Rotary Mode Control Knob
S Actuates by cable.
S Regulates the air distribution between the wind-
shield, the instrument panel, and the floor vents.
Two Push Knobs
1. The Rear Window Defogger Push Knob
S Controls the rear window defogger.
S Turns ON the rear window defogger when the
push knob is pressed and the indicator lamp is
illuminated.
2. The A/C Push Knob (if the vehicle is equipped with
air conditioning)
S Controls the A/C.
S Turns the A/C ON when the push knob is down.
However, if the blower control knob is OFF, the
A/C system is OFF, regardless of the position of
the A/C knob.
Fresh Air Control Level Or Push Knob
1. The Fresh Air Control Level
S Operates by cable.
S Switches between recirculating passenger
compartment air and bringing outside air into the
passenger compartment.
S Draws in outside air when the lever is moved to
the right.
S Recirculates inside air when the lever is moved
to the left.
2. The Fresh Air Control Push Knob
S Operates by cable.
S Switches between recirculating passenger
compartment air and bringing outside air into the
passenger compartment.
S Draws in outside air when knob is off.
S Recirculates inside air when the knob is down
with the indicator lamp illuminated.

7B – 8IMANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM
DAEWOO V–121 BL4
DIAGNOSIS
GENERAL DIAGNOSIS
TESTING THE REFRIGERANT
SYSTEM
If you suspect a problem in the refrigerant system, check
for the following conditions:
1. Check the outer surfaces of the radiator and the
condenser cores to be sure that the airflow is not
blocked by dirt, leaves, or other foreign material.
Check between the condenser and the radiator, as
well as all outer surfaces.
2. Check for restrictions or kinks in the condenser
core, the hoses, and the tubes.
3. Check the operation of the blower fan.
4. Check all the air ducts for leaks or restrictions. Low
airflow rate may indicate a restricted evaporator
core.
5. Check for slippage of the compressor clutch.
6. Check the drive belt tension.
INSUFFICIENT COOLING ”QUICK
CHECK” PROCEDURE
Perform the following ”hand–feel” procedure to get a quick
idea of whether the A/C system has the proper charge of
Refrigerant–134a. The air temperature must be above
21°C (70°F) for most models.
1. Warm up engine. Run the engine at idle.
2. Open the hood and all the doors.
3. Turn the A/C switch ON.
4. Set the temperature control to the full cold position.
5. Set the blower speed switch on the maximum
speed setting.
6. ”Hand–feel” the temperature of the evaporator out-
let pipe. The pipe should be cold.
7. Check for other problems. Refer to ”Testing the Re-
frigerant System” in this section.
8. Leak check the system. Refer to ”Leak Testing the
Refrigerant System” in this section. If you find a
leak, discharge the system and repair the leak as
required. After completing the repair, evacuate the
system and charge it.
9. If there is no leak, refer to ”Insufficient Cooling
Diagnosis” in this section.

MANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM 7B – 9
DAEWOO V–121 BL4
A/C PERFORMANCE TEST
RELATIVE
HUMIDITY
( % )AMBIENT AIR
TEMPERATURELOW SIDE
PRESSUREENGINE
SPEED
(RPM)CENTER DUCT
AIR
TEMPERATUREHIGH SIDE
PRESSURE
°C°FPsiKpa°C°FPsiKpa
2170261797451601103
2027812416520008462121462
3290261799482771910
381003322814573332296
2170261797451601103
3027812416520008462201517
32902718610502831951
381003423415593492406
217026179846162111 7
4027812617920009482271565
32902920011522952034
381003725517633642510
217026179846162111 7
5027812617920009482351620
32903222113553042096
381007149019663802620
2170271868461651138
6027812617920009482461696
32903423415593242234
381004430322723932710
2170271869481711179
70278128193200010502601793
32903624816613302275
381004732424754012765
2170271869481781227
80278130207200012542661834
32903725517633392337
2170271869481781227
90278130207200012542721875
32903826218643402344
* Test Conditions : Doors & hood opened, A/C ON, Recirculation mode, Full Cool with maximum Blower speed, No Sun-
light, Wind velocity at 8km/h (5 mph).

MANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM 7B – 11
DAEWOO V–121 BL4
LEAK TESTING REFRIGERANT
SYSTEM
Test for leaks whenever you suspect a refrigerant leak in
the system. You should also test for leaks whenever you
perform a service operation which results in disturbing the
lines or the connections. Leaks are commonly found at the
refrigerant fittings or at the connections. Leaks are com-
monly caused by the following problems:
S Improper torque.
S Damaged O–ring seals.
S Dirt or lint on the O–ring seals.
Liquid Leak Detectors
Use a liquid leak detector solution on locations such as fit-
tings. Apply the solution to the area in question with the
swab that is supplied with the solution. Look for bubbles
to appear. This will indicate the existence and the location
of any leak.
For areas where this is not practical, such as sections of
the evaporator and the condenser, an electronic leak de-
tector is more useful.
Electronic Leak Detectors
Follow the manufacturer’s instructions for calibration, op-
eration, and maintenance of an electronic leak detector.
Battery condition is especially important to the accuracy
of a portable model. Set the detector to R–134a before be-
ginning the test.
Notice : Electronic leak detectors are sensitive to wind-
shield washing solutions, solvents and cleaners, and cer-
tain vehicle adhesives. Surfaces must be clean to prevent
false readings. Make sure that all surfaces are dry to pre-
vent damage to the detector.
General Testing Instructions
1. Follow the entire path of the refrigerant system.
2. Completely circle each joint at 25 to 50 mm (1 to 2
inches) per second.
3. Hold the probe tip within 6 mm (1/4 inch) of the sur-
face.4. Do not block the air intake.
5. The audible tone changes from 1 to 2 clicks per
second into a solid alarm if there is a leak. Adjust
the balance control to maintain 1 to 2 clicks per
second.
6. Test all of the following areas, even after one leak
has been confirmed:
S Evaporator inlet and outlet.
S Receiver–drier inlet and outlet.
S Condenser inlet and outlet.
S Brazed and welded areas.
S Damaged areas.
S Hose couplings.
S Compressor rear head.
S All fittings and joints.
Testing Service Ports/Access Valves
The sealing caps provide protection for the service ports.
Make sure that these caps are not missing or loose. Al-
ways use the correct cap for each port.
Testing the Evaporator Core
Leaks in the evaporator core are difficult to find. Test the
evaporator core using the following procedure:
1. Run the blower fan at the maximum speed setting
for at least 15 minutes.
2. Turn the blower OFF.
3. Wait for 10 minutes.
4. Remove the blower motor resistor. Refer to Section
7A, Heating and Ventilation System.
5. Insert the leak detector probe as close as possible
to the evaporator core. The detector will indicate a
leak with a solid alarm.
6. Use a flashlight to search for refrigerant oil on the
core surface.
Testing the Compressor Shaft Seal
1. Blow shop air behind and in front of the compressor
clutch/pulley for at least 15 seconds.
2. Wait 1 to 2 minutes.
3. Probe the area in front of the pulley. If the detector
emits a solid alarm, there is a leak.