Mazda 626 Station Wagon, Workshop Manual

Page: 558 / 577

TROUBLESHOOTING
NO. 5 AMOUNT O F AIR BLOWN FROM VENTS DOES NOT CHANGE
5
Amount of air blown from vents does not change.
DESCRIPTION
Malfunction in blower system.
POSSIBLE
CAUSE
• Blower unit malfunction (Steps 2-4)
Diagnostic procedure
STEP
INSPECTION
ACTION
1 CHECK TO SEE WHETHER AIR BLOWS OUT
FROM VENT OR NOT
• Does air blow out?
Yes Go to next step.
No Go to Step 1 of troubleshooting index NO. 4.
2 CHECK TO SEE WHETHER MALFUNCTION IS
IN BLOWER UNIT OR ELSEWHERE
• Turn ignition switch to ON position.
• Turn fan switch on.
• Is noise coming from blower unit?
Yes Go to next step.
No Go to Step 4.
3 INSPECT BLOWER UNIT
• Inspect fan in blower unit.
— Is fan free of interference from blower unit
case?
— Is fan free of foreign material and
obstructions?
• Is fan okay?
Yes Go to next step.
No
Remove obstruction, repair or replace fan and
blower unit case, then go to Step 5.
4 INSPECT BLOWER UNIT INTAKE VENT
• Is blower unit intake vent clogged?
Yes Remove obstruction, then go to next step.
No
Check if there are any obstructions in passage
between blower unit and heater unit, then go to
next step.
5 CONFIRM THAT MALFUNCTION SYMPTOMS
DO NOT RECUR AFTER REPAIR
• Does air blow out?
Yes Troubleshooting completed. Explain repairs to
customer.
No Recheck malfunction symptoms, then repeat from
Step 1 if malfunction recurs.
NO. 6 AIRFLOW MODE DOES NOT CHANGE
6
Airflow mode does not change.
DESCRIPTION Airflow mode does not change when operating airflow mode.
POSSIBLE
CAUSE
• Airflow mode actuator (+5V signal) system malfunction (Steps 2-6, 9)
• Climate control unit (potentiometer GND signal) system malfunction (Steps 7, 8)
• Airflow mode actuator (potentiometer Input signal) system malfunction (Steps 10-12)
• Airflow mode actuator (potentiometer GND signal, motor drive signal) system malfunction
(Step 13)
• Malfunction in airflow mode actuator system (Steps 14,15)
• Malfunction in heater unit airflow mode door (Steps 16,17)
Diagnostic procedure
• When performing an asterisked(*) troubleshooting inspection, shake the wiring harness and connectors while
doing the inspection to discover whether poor contact points are the cause of any intermittent malfunctions. If
there is a problem, check to make sure connectors, terminals and wiring harness are connected correctly and
undamaged.
STEP INSPECTION ACTION
1 CHECK CIRCUITS COMMON TO BOTH AIR
MIX ACTUATOR AND AIRFLOW MODE
ACTUATOR
• Does temperature of blown air change when
operating temperature control lever?
Yes Go to Step 9.
No Go to next step.
U -24