Daewoo Nubira Owner's Manual page 427

7A – 6IHEATING AND VENTILATION SYSTEM
Step
20 Replace the thermostat. Refer to Section 1D, En-
gine Cooling.
Is the repair complete?
21 Reinstall the thermostat.
Is the repair complete?
22 Inspect the heater hoses for proper installation.
Are the heater hoses reversed?
23 Reinstall the heater hoses properly.
Is the repair complete?
24
1. Back flush the heater core.
2. Drain the cooling system.
3. Replace the coolant.
4. Warm the engine to an average operating tem-
perature.
5. Feel the heater inlet hose and the heater outlet
hose.
Is the heater inlet hose hot and the heater outlet
hose warm?
25 Replace the heater core.
Is the repair complete?
26 Recheck the system using the "Control Settings/
Correct Results" tests. Refer to "Improper Air Deliv-
ery or No Mode Shift" in this section.
Is the repair complete?
27 Check for airflow from the defroster or the vent out-
lets.
Is there high airflow from the defroster or vent out-
lets?
28 Check the heater door at the floor and the vent door
to get the proper airflow, verify proper operation, and
repair, as required.
Is the repair complete?
29 Turn the mode knob to defrost.
Is the defroster airflow OK?
30
1. Remove the heater outlet and check for ob-
structions.
2. Remove any obstructions in the heater outlet.
Is the repair complete?
31 Check for airflow change at various blower speeds.
Does the blower speed increase as the control is
turned from 1 to 4?
32 Check for obstructions in the system at the blower
inlet and at the air filter, if the vehicle is equipped with
one.
Are there any obstructions?
33 Remove the obstructions in the system at the blower
inlet or replace a clogged filter.
Are the repairs complete?
Action Value(s) Yes
System OK
System OK
Go to Step 23
System OK
System OK
System OK
System OK
Go to Step 28
System OK
Go to Step 30
System OK
Go to Step 32
Go to Step 33
System OK
No
Go to Step 24
Go to Step 25
Go to Step 27
Go to Step 29
Go to Step 31
Go to "Blower
Electrical"
Go to Step 34
DAEWOO V–121 BL4