With Dual Zone
INSUFFICIENT HEAT^ Check engine coolant level. Fill if necessary.
^ Check duct work for proper installation.
^ Check blower operation.
^ Check for proper operation of temperature door (binding, sticking, etc.
^ Check for in-line restrictions to heater core as follows:
- Start engine and allow to warm up.
- Set blower to "HI."
- Feel heater core inlet and outlet hoses. Inlet hose should be hot. Outlet hose should be slightly cooler. If not, replace heater core.
INSUFFICIENT COOLING
NOTE: Try the following quick checks before using trouble-tree diagnosis.
^ Check outer surfaces of radiator and condenser cores to be sure air flow is not restricted by dirt, leaves, or other foreign material.
^ Check evaporator and condenser core hoses, tubes, etc, for restrictions or kinks.
^ Check for refrigerant leaks.
^ Check air ducts for leaks or restrictions (low air flow may indicate restricted evaporator core).
^ Check compressor clutch for slippage.
^ Check drive belt for improper tension.
The following procedure can be used to quickly determine whether or not A/C system has proper charge of R-12 (providing air temperature is above 21°C/7O°F). This check simplifies system diagnosis by pinpointing problem to amount of R-12 charge or by eliminating low charge possibility from overall checkout.
^ Engine: warm (idling at normal speed)
^ Hood and body doors open.
^ A/C mode: "AUTO."
^ Set temperature: 16°C (6O°F)
^ Blower: "HI."
^ Hand feel temperature of evaporator inlet pipe after orifice (expansion) tube and accumulator surface with compressor engaged.
a. Inlet pipe cooler than accumulator surface or inlet pipe has frost accumulation (accumulator surface warmer).
- Recover Refrigerant.
- Check for plugged Expansion (Orifice) Tube and repair as necessary.
- Check for restriction(s) in high side of system and repair as necessary.
- Evacuate and Charge.
b. Both same temperature and both some degree cooler than ambient.
- Proceed with the following trouble-tree diagnosis.
Diagnosis: Air Conditioning (part 1):
Trouble-Tree Diagnosis Part 1
Diagnosis: Air Conditioning (part 2):
Trouble-Tree Diagnosis Part 2
Diagnosis: Air Conditioning (part 3):
Trouble-Tree Diagnosis Part 3