Air Goes Out Of Control: 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 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 2 .	Replace the A/C control panel. Refer to REMOVAL .
2 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 3 .	Replace the A/C control panel. Refer to REMOVAL .
3 CHECK HARNESS. Turn the ignition switch to OFF. Disconnect the power transistor connector. Use a tester to measure the resistance between the power transistor connector and chassis ground. Connector & terminal (i183) No. 5 - Chassis ground:	Is the resistance less than 1 Ω?	Repair or replace the short circuit portion of the harness (i183) No. 5 - (i185) No. 1 between blower motor and power transistor.	Go to step 4 .
4 CHECK HARNESS. Remove the A/C CM. Turn the ignition switch to ON. Use a tester to measure the resistance between the power transistor connector and chassis ground. Connector & terminal (i183) No. 1 - Chassis ground:	Is the resistance less than 1 Ω?	Repair or replace the short circuit portion of the harness (i183) No. 1 - (i181) No. 9 between A/C CM and power transistor.	Go to step 5 .
5 CHECK HARNESS. Connect the disconnected connectors. Turn the ignition switch to ON. Use a tester to measure the voltage between the power transistor connector and chassis ground. Connector & terminal (i183) No. 1 (+) - Chassis ground (-):	Is the voltage approx. 10 V when the fan switch is set to 1st, and approx. 1 V when set to 6th?	Replace the power transistor. Refer to REMOVAL .	Go to step 6 .
6 CHECK A/C CM. Turn the fan switch to OFF. Disconnect the power transistor connector. Use a tester to measure the resistance between the power transistor connector and chassis ground. Connector & terminal (i183) No. 1 - Chassis ground:	When the fan switch is OFF and other than OFF, does the resistance change?	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 MOTOR CIRCUIT. Turn the ignition switch to OFF. Disconnect the blower fan switch connector and blower resistor connector. Use a tester to measure the resistance between each terminal and chassis ground. Connector & terminal (i182) No. 4 - Chassis ground: (i15) No. 5 - Chassis ground: (i15) No. 6 - Chassis ground: (i15) No. 3 - Chassis ground: (i15) No. 2 - Chassis ground:	Is the resistance less than 1 Ω?	Repair or replace the short circuit of the harness.	Go to step 2 .
2 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 .