Content .. 176 177 178 179 ..

Daewoo Nubira. Manual - part 178

7A – 8

HEATING AND VENTILATION SYSTEM

DAEWOO V–121 BL4

Step

Yes

Value(s)

Action

1.  Turn the ignition ON.
2.  Turn the blower motor switch to 4.
3.  Check the blower motor ground.

Is ground OK?

Go to Step 9

Go to Step 8

Repair the blower motor ground.
Is the repair complete?

System OK

Check the motor connector with a 12–volt test light.
Does the test light come on?

Go to Step 10

Go to Step 11

Repair the open in the feed wire from the resistor
block to the blower motor.
Is the repair complete?

System OK

Use the 12–volt test light to check the power feed
terminal on the blower speed switch.
Does the light come on?

Go to Step 12

Go to Step 13

Replace the blower speed switch.
Is the repair complete?

System OK

Repair the open in the power wire from the blower
speed switch to the fuse panel.
Is the repair complete?

System OK

Does the blower fail to operate at speed 4?

Go to Step 15

Go to Step 21

Check fuse EF2 in the engine fuse block.
Is the fuse blown?

Go to Step 16

Go to Step 17

1.  Turn the ignition ON.
2.  Turn the blower motor switch to 4.
3.  Use a short detector to locate the following

possible shorts:

From the engine fuse panel to the blower

HI relay.

From the blower HI relay to the blower mo-

tor.

4. Repair any short.
5. Replace the EF2.

Is the repair complete?

System OK

1.  Turn the ignition ON.
2.  Turn the blower motor switch to 4.
3.  Check for 12 volts on the blower HI relay coil

terminal from the blower speed switch terminal
A2.

Is this voltage present?

Go to Step 18

Go to Step 19

Replace the blower speed switch.
Is the repair complete?

System OK

1. Turn the ignition OFF.
2. Check for opens in the following locations:

Fuse EF2 to the blower HI relay.

Blower speed switch to the blower HI relay.

Blower HI relay to ground.

Blower HI relay to the blower motor.

3. Repair any opens.

Is the repair complete?

System OK

Go to Step 20

HEATING AND VENTILATION SYSTEM 7A – 9

DAEWOO V–121 BL4

Step

Yes

Value(s)

Action

Replace the blower HI relay.
Is the repair complete?

System OK

1. 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 23

Go to Step 22

Replace the resistor block.
Is the repair complete?

System OK

1. 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 25

Go to Step 24

Replace the blower speed switch.
Is the repair complete?

System OK

Repair 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
KNOB

TEMP.

CONTROL

BLOWER

MOTOR

SWITCH

BLOWER

SPEED

POWER

VENT

OUTLET

FLOOR

OUTLET

DEFROST

OUTLET

SIDE

WINDOW

OUTLET

Vent

Cold

Off

No Airflow

Vent

Cold

High

Ambient

Airflow

No Airflow

Floor

Cold to Hot

High

No Airflow

Cold to Hot

Airflow

Minimum

Cold to Hot

Airflow

Minimum

Cold to Hot

Airflow

Defroster

Cold to Hot

High

No Airflow

Minimum

Cold to Hot

Airflow

Cold to Hot

Airflow

Minimum

Cold to Hot

Airflow

If any of these settings does not produce the correct results, perform the following diagnostic procedure.

7A – 10

HEATING AND VENTILATION SYSTEM

DAEWOO V–121 BL4

Step

Action

Value(s)

Yes

Verify the customer’s complaint.
Are the customer’s concerns verified?

Go to Step 2

System OK

Examine the affected door in the unit for proper at-
tachment to the vacuum actuator.

Check the actuator connection to the door.

Check that the vacuum hose is connected

properly.

Is everything connected properly?

Go to Step 4

Go to Step 3

Repair, as necessary.
Is the repair complete?

System OK

1. 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 5

Go to Step 3

Check the travel of the actuator by turning the con-
trol knob with the engine running.
Is the actuator travel OK?

Go to Step 6

Go to Step 7

1. Reinstall the actuator.
2. Recheck the system using the ”Control Set-

tings/Correct Results” tests in this procedure.

Does the system perform properly?

System OK

Go to Step 9

1. 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 8

Go to Step 9

Repair the vacuum hose or control, as necessary.
Is the repair complete?

System OK

Go to Step 9

Recheck the system using the ”Control Settings/
Correct Results” tests in this procedure.
Is the repair complete?

System OK

Go to Step 10

Check for airflow from the defroster or the vent out-
lets.
Is there high airflow from the defroster or the vent
outlets?

Go to Step 11

Go to Step 12

Adjust the heater door at the floor and the vent door
to get the proper airflow.
Is the repair complete?

System OK

Turn the mode knob to defrost.
Is the defroster airflow OK?

Go to Step 13

Go to Step 14

1.  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

Check the blower speeds fora change in the airflow.
Does the blower speed increase as the control is
turned from 1 to 4?

Go to Step 15

Go to ”Blower

Electrical”

HEATING AND VENTILATION SYSTEM 7A – 11

DAEWOO V–121 BL4

Step

Yes

Value(s)

Action

1. Check for obstructions in the system at the

blower inlet and check the air filter, if equipped.

2. Remove any obstructions at the blower inlet

and replace the filter if it is clogged.

Is the repair complete?

System OK

Go to Step 16

1. Turn the blower motor switch to 4.
2. Turn the temperature control knob from full hot

to full cold.

3. Listen for an airflow change.

Does the airflow change?

Go to Step 17

Go to Step 18

1. Check the temperature door, the cable, the

linkage, and the control.

2. Turn the temperature control knob to full hot.

Is the repair complete?

System OK

1. 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

Step

Action

Value(s)

Yes

Verify the customer’s complaint.
Are the customer’s concerns verified?

Go to Step 2

System OK

Is there too much heat when the mode switch is in
the floor position?

Go to Step 3

Go to Step 9

Is there objectionable defroster bleed?

Go to Step 4

Go to Step 5

1. 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

1. Turn the A/C OFF on vehicles equipped with

A/C.

2.  Turn the blower motor switch to 4.
3.  Turn the temperature to full hot.
4.  Turn the ignition ON.
5.  Start the engine.
6.  Check for airflow from the floor outlets.
7.  Check the floor outlet attachment.

Is the airflow high?

Go to Step 6

Go to Step 8

Check for a change in the airflow at different blower
speeds.
Does the airflow change as the setting for the blower
motor speed switch is changed?

Go to Step 7

Go to ”Blower

Electrical”

1. Check the temperature door travel, the cable,

and the linkage.

2. Turn the temperature control knob to full cold.
3. Check for full hot.

Is the repair complete?

System OK

Content .. 176 177 178 179 ..