CONTENTS
FAULTY COMPONENTS
HEATING AND AIR COND.
HEATER OR DEFROSTER INOPERATIVE

SYSTEM BLOWS AIR

CONDITION(S)

• HEATER OR WINDSHIELD DEFROSTER INOPERATIVE
• SYSTEM BLOWS AIR, BUT IT IS NOT WARM

POTENTIAL CAUSE(S)

CHECK THESE FIRST:

1. FAULTY THERMOSTAT (STUCK OPEN)
Replace thermostat.

2. COLLAPSED OR CLOGGED HEATER HOSE
Replace heater hose.

3. CLOGGED HEATER CORE
Backflush and clean cooling system.

4. LOW COOLANT LEVEL
Add coolant if necessary.

CHECK THESE NEXT:

5. FAULTY HEATER CONTROL VALVE
Have heater control valve professionally replaced.

6. CROSSED, COLLAPSED OR KINKED VACUUM LINES
Have heater vacuum lines professionally serviced.

7. BROKEN TEMPERATURE CONTROL LEVER
Have temperature control lever professionally replaced.

8. CLOGGED WATER PUMP BYPASS HOSE
Replace water pump bypass hose.

CHECK THESE LAST:

9. PLUGGED BYPASS OUTLET AT THERMOSTAT HOUSING
Backflush and clean cooling system.

10. LOCKED FAN CLUTCH
Have fan clutch professionally replaced.

11. SHORTED FAN SWITCH ON ELECTRIC COOLING FAN
Have fan switch professionally replaced.

CONTENTS
AIR CONDITIONER NOT COLD
SYSTEM DOES NOT BLOW AIR