No. 6 A/C System Noise Operation or Water Leak Malfunction

Flowchart No.6
Symptom A/C system noise operation or water leak malfunction
Related components Blower motor, airflow mode actuator, expansion valve, air intake actuator, A/C drive belt, condenser fan/shroud assembly

Part 1 Of 2:

Part 2 Of 2:

System Operating Inspection
Determine the malfunction area by following system operating inspection. [Interior vehicle A/C system noise]
1. Turn the IG SW to ON.
2. Cycle the fan switch through all 4 fan speeds. (Leave fan in 4th speed.)
3. Cycle the mode switch through VENT, VENT-FLOOR, FLOOR, FLOOR/DEF, and DEF modes.
4. Cycle the REC/FRESH switch through the fresh and recirculation modes.
5. Cycle the air mix lever from full cold through full hot.

Operation
- The fan speed vent outlet volume quietly increases as each higher tan speed in selected.
- The airflow mode actuator quietly redirects the blower airflow through each proper vent location as the mode switches are selected.
- In the recirculation mode, the air intake actuator quietly closes the air intake door, closing the blower case to external vehicle airflow.
- In the fresh mode, the air intake actuator quietly opens the air intake door, opening the blower case to external vehicle airflow.
- The air mix lever smoothly and quietly redirects the heater unit heat door from hot to cold and vice versa.
- Condensation from A/C operation collects in the bottom of the evaporator and is drained through the firewall evaporator drain plug.
- When the vehicles A/C system is operated, no mildew odor is present in the vehicle.

6. If noise is pronounced and changes when cycling the fan speed through one or all fan speed positions, go to step 1.
7. If the vent outlet/under dash noise is pronounced in all modes, or the outlet volume is low at one or more outlet positions, go to step 2.
8. If the vent outlet/under dash noise is pronounced in one mode, or the outlet volume is constant at all outlet positions, go to step 3.
9. If a constant under dash whopping noise is heard, go to step 4.
10. If the under dash noise is pronounced when selecting the recirculation mode, go to step 5.
11. If the under dash noise is pronounced when selecting the fresh mode, go to step 5.
12. If the noise is pronounced when the air mix lever is moved from maximum hot to maximum cold or vice versa, go to step 6.
13. If a plugged drain causes water to leak into the right front cabin area, go to step 7.

[Exterior vehicle A/C system noise]
1. Start the engine.
2. Set the fan switch to the 4th position.
3. Turn the A/C switch on.
4. Set the air mix lever at the maximum cold position.
5. If noise is not audible, go to the next step.
6. Depress the brake, and increase the engine to 2,500 rpm.

Operation
- The magnetic clutch engages (an audible click is heard), and should remain engaged until an outlet vent temperature reading of 2-4 °C {36-39 °F} is obtained. At this point, the magnetic clutch cycles off (another click is heard) until the vent temperature reading reaches 4-5 ° C {39-41 °F}, then the magnetic clutch engages again.
- As the A/C switch is on, the condenser fan is turned on until the magnetic clutch is disengaged, at which time the condenser fan is cycled off.

7. If a constant clicking noise is heard when the magnetic clutch is engaged, and the clicking stops when the engine speed increased, go to step 9.
8. If the noise originates from inside the magnetic clutch during refrigerant charging, go to step 9.
9. If the noise originates from the magnetic clutch afier the refrigerant system parts are replaced, go to step 10.
10. If a rattling or knock is heard when the magnetic clutch is engaged, go to step 11.
11. If a squeal is heard when the magnetic clutch is engaged, go to step 12.
12. If a noise is heard from the condenser fan area when the A/C is engaged and the condenser fan is operating, go to step 15.