Air Does Not Come Out, Or Airflow Capacity Is Insufficient: Wiring Diagram

Air Conditioning System. See appropriate SYSTEM WIRING DIAGRAM article.

Fig 1: Auto A/C - Wiring Diagram

Courtesy of SUBARU OF AMERICA, INC.

Step	Check	Yes	No
1 CHECK BLOWER OPERATION. Using Subaru Select Monitor, display the following data in "Read Current Data". Air mix door actuator position (driver's side) Air mix door actuator position (passenger's side) (with left/right independent air conditioner) Blower Fan Level Set the temperature control switch to MAX COOL, and increase or decrease the A/C control panel fan switch. (For vehicles with left/right independent air conditioner, perform setting on both sides.)	Do "Air mix door actuator position (driver's side)" and "Air mix door actuator position (passenger's side)" (with left/right independent air conditioner) indicate "0%"? Does "Blower Fan Level" increase or decrease in accordance with the fan switch operation?	Go to step 2 .	Go to step 5 .
2 CHECK AIRFLOW CAPACITY. Set the temperature control switch to LO (For vehicles with left/right independent air conditioner, perform setting on both seats.), and set the fan switch of the A/C control panel to MAX and set the FRESH/RECIRC switch to RECIRC.	Is the airflow capacity insufficient for the same model?	Go to step 3 .	System is normal.
3 CHECK A/C FILTER. Check the A/C filter. Refer to INSPECTION .	Is the A/C filter normal?	Go to step 4 .	Clean or replace the A/C filter.
4 CHECK EACH DUCT. Check each duct joint for disconnection or clogging. Refer to INSPECTION , Air Vent Grille. Refer to INSPECTION , Heater Duct. Refer to INSPECTION , Heater Vent Duct.	Is each duct normal?	Go to step 5 .	Repair the faulty duct.
5 CHECK A/C CONTROL PANEL. Turn the ignition switch to ON. Set the fan switch to maximum position. Using the Subaru Select Monitor, check "Blower Fan Level" of the current data from the A/C diagnosis.	Does "Blower Fan Level" indicate "31"?	Go to step 6 .	Replace the A/C control panel. Refer to REMOVAL .
6 CHECK A/C CONTROL PANEL. Set the fan switch to minimum position. Using the Subaru Select Monitor, check "Blower Fan Level" of the current data from the A/C diagnosis.	Does "Blower Fan Level" indicate "1"?	Go to step 7 .	Replace the A/C control panel. Refer to REMOVAL .
7 CHECK CONNECTOR. Check the connectors (i80) and (i181) for poor contact.	Is there poor contact of connector?	Repair the connector.	Go to step 8 .
8 CHECK FUSE. Remove fuse No. 22 and 7 from fuse & relay box, and fuse No. 4 and 5 from the main fuse box. Check the condition of fuse.	Is the fuse blown out?	Replace the fuse.	Go to step 9 .
9 CHECK BLOWER MOTOR RELAY ON SIGNAL. Stop the engine. Turn the fan switch to OFF. Turn the ignition switch to ON. Using a tester, measure the voltage between the A/C CM connector (i181) and chassis ground. Connector & terminal (i181) No. 20 (+) - Chassis ground (-):	Is the voltage 10 V or more?	Go to step 10 .	Check for an open or short circuit in the harness between the F/B fuse No. 22 and ECM. Check the blower relay connector and relay unit. Refer to CHECK RELAY .
10 CHECK BLOWER MOTOR RELAY ON SIGNAL. Start the engine. Turn the fan switch to ON. Using a tester, measure the voltage between the A/C CM connector (i181) and chassis ground. Connector & terminal (i181) No. 20 (+) - Chassis ground (-):	Is the voltage 0 V?	Go to step 11 .	Replace the A/C CM. Refer to REMOVAL .
11 CHECK BLOWER MOTOR POWER SUPPLY CIRCUIT. Turn the ignition switch to ON. Turn the fan switch to ON. Use a tester, measure the voltage between the blower motor connector (i185) and chassis ground. Connector & terminal (i185) No. 2 (+) - Chassis ground (-):	Is the voltage 10 V or more?	Go to step 12 .	Check for an open in the blower motor power supply line harness and for disconnection of the connectors (B38) and (i3). Check the blower relay connector and relay unit. Refer to CHECK RELAY .
12 CHECK BLOWER MOTOR UNIT. Check the blower motor. Refer to INSPECTION .	Is the blower motor OK?	Go to step 13 .	Replace the blower motor. Refer to REMOVAL .
13 CHECK HARNESS. Disconnect the power transistor and A/C CM connector. Using a tester, measure the resistance between harness terminals. Connector & terminal (i185) No. 1 - (i183) No. 5: (i183) No. 3 - (i181) No. 8: (i183) No. 1 - (i181) No. 9: (i183) No. 4 - Chassis ground:	Is the resistance less than 1 Ω?	Go to step 14 .	Repair or replace the open circuit of harness.
14 CHECK HARNESS . Use a tester to measure the resistance of harness between the power transistor connector (i183) and chassis ground. Connector & terminal (i183) No. 1 - Chassis ground: (i183) No. 3 - Chassis ground:	Is the resistance less than 1 Ω?	Repair or replace the short circuit of the harness.	Go to step 15 .
15 CHECK POWER TRANSISTOR. Replace the power transistor with a properly functioning part.	Does the blower motor rotate?	Replace the power transistor. Refer to REMOVAL .	Replace the A/C CM Refer to REMOVAL .

Manual A/C

Air Conditioning System. See appropriate SYSTEM WIRING DIAGRAM article.

Fig 1: Manual A/C - Wiring Diagram

Courtesy of SUBARU OF AMERICA, INC.

Step	Check	Yes	No
1 CHECK BLOWER OPERATION. Set the temperature control dial to MAX COOL, and increase or decrease the fan dial.	Does the airflow capacity increase or decrease in accordance with the dial operation?	Go to step 2 .	Go to step 5 .
2 CHECK AIRFLOW CAPACITY. Set the temperature control switch to MAX COOL, set the fan switch to MAX and set the FRESH/RECIRC switch to RECIRC.	Is the airflow capacity insufficient for the same model?	Go to step 3 .	System is normal.
3 CHECK A/C FILTER. Check the A/C filter. Refer to INSPECTION .	Is the A/C filter normal?	Go to step 4 .	Clean or replace the A/C filter.
4 CHECK EACH DUCT. Check each duct joint for disconnection or clogging. Refer to INSPECTION , Air Vent Grille. Refer to INSPECTION , Heater Duct. Refer to INSPECTION , Heater Vent Duct.	Is each duct normal?	Go to step 5 .	Repair the faulty duct.
5 CHECK CONNECTOR. Check the connectors (i184), (i185), (i182), (i15) and (B38) for poor contact.	Is there poor contact of connector?	Repair the connector.	Go to step 6 .
6 CHECK FUSE. Remove the fuse No. 22 of the fuse & relay box and the fuses No. 4 and No. 5 of the main fuse box. Check the condition of fuse.	Is the fuse blown out?	Replace the fuse.	Go to step 7 .
7 CHECK BLOWER MOTOR RELAY ON SIGNAL. Stop the engine. Turn the fan switch to OFF. Turn the ignition switch to ON. Use a tester to measure the voltage between the blower fan switch and chassis ground. Connector & terminal (i15) No. 4 (+) - Chassis ground (-):	Is the voltage 10 V or more?	Go to step 8 .	Check for an open or short circuit between the F/B fuse No. 22 and blower fan switch. Check the blower relay connector and relay unit.
8 CHECK BLOWER MOTOR RELAY ON SIGNAL. Start the engine. Turn the fan switch to OFF. Turn the ignition switch to ON. Use a tester to measure the voltage between the blower fan switch and chassis ground. Connector & terminal (i15) No. 4 (+) - Chassis ground (-):	Is the voltage 0 V?	Go to step 9 .	Replace the A/C control panel. Refer to MANUAL A/C MODEL .
9 CHECK BLOWER MOTOR POWER SUPPLY. Turn the ignition switch to ON. Turn the blower switch to ON. Use a tester to measure the voltage between the blower motor connector and chassis ground. Connector & terminal (i185) No. 2 (+) - Chassis ground (-):	Is the voltage 10 V or more?	Go to step 10 .	Check for an open in the blower motor power supply harness, and check the connectors (B38) and (i3). Check the blower relay connector and relay unit.
10 CHECK BLOWER MOTOR. Check the blower motor. Refer to INSPECTION .	Is the blower motor OK?	Go to step 11 .	Replace the blower motor. Refer to REMOVAL .
11 CHECK HARNESS. Disconnect the connector from blower motor, blower resistor and blower fan switch. Use a tester to measure the resistance of the harness between terminals. Connector & terminal (i185) No. 1 - (i182) No. 4: (i185) No. 1 - (i15) No. 4: (i182) No. 1 - (i15) No. 2: (i182) No. 2 - (i15) No. 6: (i182) No. 1 - (i15) No. 3:	Is the resistance less than 1 Ω?	Go to step 12 .	Repair or replace the open circuit of harness.
12 CHECK BLOWER RESISTOR. Check the blower resistor. Refer to INSPECTION .	Is the blower resistor OK?	Replace the A/C control panel. Refer to MANUAL A/C MODEL .	Replace the blower resistor. Refer to REMOVAL .