Mazda CX-7 2007 Workshop Manual page 1135

NO.6 WINDSHIELD FOGGED
6 Windshield fogged.
• A/C compressor does not operate while airflow mode is in DEFROSTER or HEAT/DEF modes.
• Air intake mode does not change to FRESH while airflow mode is in DEFROSTER or HEAT/DEF
DESCRIPTION
modes.
• Climate control unit (B+ signal) system malfunction
• Air intake actuator malfunction
POSSIBLE
• Climate control unit (RECIRCULATE, FRESH signal) system malfunction
CAUSE
• A/C unit air intake door malfunction
• 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, inspect to make sure connectors, terminals and wiring harness are connected correctly and
undamaged.
Diagnostic procedure
STEP
1 COOL AIR BLOW OUT INSPECTION
• When both the A/C and airflow volume
control dial in the climate control unit are on,
does cool air blow out from the front vent?
2 INSPECT CLIMATE CONTROL UNIT POWER
SUPPLY FUSE FOR B+ SIGNAL
• Is the climate control unit power supply fuse
for B+ signal normal?
3 INSPECT AIR INTAKE ACTUATOR
• Inspect the air intake actuator.
— Is there grease on the link?
— Is the link securely and properly
positioned?
— Is the link free of obstructions?
• Are the above items normal?
*4 INSPECT WIRING HARNESS BETWEEN
FUSE BLOCK AND CLIMATE CONTROL UNIT
FOR CONTINUITY
• Disconnect the climate control unit connector
(24-pin).
• Turn the ignition switch to the ON position.
• Measure the voltage at the following climate
control unit terminal (B+ signal).
— R (full-auto air conditioner)
— P (manual air conditioner)
• Is the voltage approx. 12 V?
*5 INSPECT WIRING HARNESS BETWEEN
CLIMATE CONTROL UNIT AND GROUND
FOR VOLTAGE
• Measure the voltage at the following climate
control unit terminal (Ground).
— D (full-auto air conditioner)
— L (manual air conditioner)
• Is the voltage approx. 0V?
6 VERIFY WHETHER MALFUNCTION IS IN A/C
UNIT AIR INTAKE DOOR OR ELSEWHERE
• Turn the ignition switch to the LOCK position.
• Connect the climate control unit connector
(24-pin).
• Remove the air intake actuator.
• Turn the ignition switch to the ON position.
• Set the airflow volume control dial to 4th
position.
• Does the air intake mode (RECIRCULATE,
FRESH) change smoothly when the air
intake link is operated by hand?
SYMPTOM TROUBLESHOOTING
INSPECTION
Yes Go to the next step.
No Go to Step 1 of troubleshooting index No.8.
Yes Go to the next step.
No Inspect for a short to ground on blown fuse circuit.
Repair or replace if necessary. Install appropriate amperage
fuse.
Yes Go to the next step.
No Apply grease or install the link properly and securely,
remove obstruction, then go to Step 14.
Yes Go to the next step.
No Repair the wiring harness between the fuse block and
climate control unit, then go to Step 14.
Yes Go to the next step.
No Repair the wiring harness between the climate control unit
and ground, then go to Step 14.
Yes Go to the next step.
No Go to Step 12.
id070300800900
ACTION
07-03–11
07-03