Mazda 626 Station Wagon, Workshop Manual

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TROUBLESHOOTING
STEP INSPECTION
ACTION
17 VERIFY THAT HEATER UNIT AIR MIX DOORS
DO NOT HAVE ANY FOREIGN MATERIAL OR
OBSTRUCTION
• Is there any foreign material or obstructions on
any heater unit door?
Yes Remove material/obstruction, then go to Step 19.
No Go to next step.
18 INSPECT HEATER UNIT AIR MIX DOORS
• Are all doors within heater unit securely and
properly positioned?
• Inspect heater unit doors.
— Are doors cracked or damaged?
— Are doors securely and properly installed?
• Are they okay?
Yes Replace climate control unit, then go to next step.
(Malfunction in climate control unit temperature
control lever circuit)
No
Replace or install door(s) in proper position, then
go to next step.
19 CONFIRM THAT MALFUNCTION SYMPTOMS
DO NOT RECUR AFTER REPAIR
• Does temperature change when operating
temperature control lever?
Yes Troubleshooting completed. Explain repairs to
customer.
No Recheck malfunction symptoms, then repeat from
Step 1 if malfunction recurs.
NO. 9 AIR FROM VENTS NOT COLD ENOUGH
9 Air from vents not cold enough.
DESCRIPTION Magnetic clutch operates but A/C system malfunctions.
POSSIBLE
CAUSE
• Drive belt malfunction (Step 1)
• Malfunction in blower unit or condenser (Steps 4, 5)
• Malfunction in receiver/drier, expansion valve (valve closes too much); or else expansion valve
heat-sensing tube installed incorrectly (Steps 8, 9)
• Malfunction in refrigerant lines (Steps 10-13)
• A/C compressor system malfunction; insufficient compressor oil (Step 16)
• Too much compressor oil; expansion valve heat-sensing tube installed incorrectly; malfunction in
expansion valve (valve opens too much); malfunction in heater unit air mix link system (Steps
18-20)
Diagnostic procedure
STEP INSPECTION ACTION
1 INSPECT DRIVE BELT
• Inspect drive belt.
• Is it okay?
Yes Go to next step.
No Adjust or replace drive belt, then go to Step 21.
2 INSPECT REFRIGERANT SYSTEM
PERFORMANCE
• Carry out refrigerant system performance test.
• Is operation normal?
Yes Operation is normal. (Recheck malfunction
symptoms.)
No Go to next step.
3 CHECK TO SEE WHETHER MALFUNCTION IS
IN BLOWER UNIT INTAKE AND CONDENSER
OR ELSEWHERE
• Are refrigerant high-pressure and low-pressure
values both high?
Yes
Go to next step.
No
Go to Step 6.
4
INSPECT BLOWER UNIT INTAKE
• Is blower unit intake clogged?
Yes Remove obstruction, then go to Step 21. (If air
does not reach evaporator within cooling unit,
heat exchange does not occur and refrigerant
pressure becomes high. Therefore, removal of
obstruction is necessary.)
No Go to next step.
5
INSPECT CONDENSER
• Inspect condenser.
• Is it okay?
Yes Adjust refrigerant to specified amount, then go to
Step 21. (Excessive amount of refrigerant.)
No Replace condenser, or repair and clean
condenser fins, then go to Step 21.
6 CHECK TO SEE WHETHER MALFUNCTION IS
IN EXPANSION VALVE, RECEIVER/DRIER AND
REFRIGERANT LINES OR ELSEWHERE
• Are refrigerant high-pressure and
low-pressure values both low?
Yes Go to next step.
No Go to Step 14.
U-31