For 1990-2009 cars

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the entire HVAC System Check performed? | -- | Go to Step 2 | Go to HVAC System Check
2 | Were you sent here for a poor cooling concern of the passenger compartment? | -- | Go to Step 3 | Go to Step 4
3 | Does the A/C compressor clutch engage when the A/C button is depressed? | -- | Go to Step 5 | Go to HVAC Compressor Clutch Does Not Engage
4 | Before proceeding with the following table, check and make sure that:

• | the engine is reaching normal operating temperature.

• | both upper and lower radiator hoses have become hot.

• | both inlet and outlet heater hoses have become hot.

• | the cooling system is operating normally.

Is the cooling system operating normally?

--

Go to Step 5

Go to Heating Insufficient

5 |

1. Disconnect the heater-A/C control connector C2.
2. Turn the ignition switch to the RUN position.
3. Connect a test light from the heater-A/C control connector C2 terminal E and ground.

Is the test light on?

--

Go to Step 6

Go to Step 7

6 | Backprobe with a test light between the heater-A/C control connector C2 terminal C and ground. Is the test light on? | -- | Go to Step 8 | Go to Step 9
7 | Repair a poor connection or open in CKT 640 between the heater-A/C control connector C2 terminal E and S202. Is the repair complete? | -- | Go to Step 16 | --
8 | Backprobe with a test light between the heater-A/C control connector C2 terminal K and B+. Is the test light on? | -- | Go to Step 10 | Go to Step 11
9 | Repair the poor connection or open in CKT 241 between the heater-A/C control connector C2 terminal C and S264. Is the repair complete? | -- | Go to Step 16 | --
10 |

1. Turn the ignition switch to the OFF position.
2. Disconnect the electric slave actuator connector.
3. Disconnect the auxiliary heater-A/C control connector C1.
4. Using a J 39200 , check for continuity in CKT 733 between the heater-A/C control connector C2 terminal G and the electric slave actuator terminal 8.
5. Using a J 39200 , check for continuity in CKT 733 between the heater-A/C control connector C2 terminal G and the auxiliary heater-A/C control connector C1 terminal 4.

Is there continuity for both tests?

--

Go to Step 12

Go to Step 13

11 | Repair the poor connection or open in CKT 150 between the heater-A/C control connector C2 terminal K and S213. Is the repair complete? | -- | Go to Step 16 | --
12 | Using a J 39200 , check for continuity in CKT 733 between the heater-A/C control connector C2 terminal G and ground. Is circuit 733 shorted to ground? | -- | Go to Step 14 | Go to Step 15
13 | Repair the poor connection or open in CKT 733. Is the repair complete? | -- | Go to Step 16 | --
14 | Repair the short to ground in CKT 733. Is the repair complete? | -- | Go to Step 16 | --
15 | Replace the heater-A/C control. Refer to Control Assembly Replacement . Is the repair complete? | -- | Go to Step 16 | --
16 |

1. Turn the ignition switch to the OFF position.
2. Reconnect all connectors/components disconnected.

Have all repairs been made?

--

Go to HVAC System Check

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