GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you review the Control Assembly Description and perform the necessary inspections?

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Go to Step 2

Go to Symptoms

2

Inspect the A/C Cruise fuse in the fuse block.

Is the A/C Cruise fuse open?

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Go to Step 3

Go to Step 4

3

Locate and repair a short to ground in the B+ supply to the Heater-A/C control and the Temperature Control Electric actuator. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is the repair complete?

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Go to Step 9

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4

  1. Place the ignition switch in the on position.
  2. Connect a test lamp between the Temperature Control Electric actuator harness connector terminal 8 and ground.

Does the test lamp light?

--

Go to Step 6

Go to Step 5

5

Locate and repair a poor connection or an open in the Temperature Control Electric actuator control circuit . Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 9

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6

Use a test lamp connected to B+ to probe the Temperature Control Electric Actuator connector terminal 7

Does the test lamp light?

 

Go to Step 8

Go to Step 7

7

Repair a fault in the Temperature Control Electric Actuator ground circuit. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 9

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8

A fault has occurred in the vacuum selector, vacuum source, vacuum actuators, vacuum hoses to actuators, linkage from actuators to values, or faulty valves. Refer to Air Delivery Improper for further diagnosis.

Is the action complete?

--

Go to Step 9

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9

Verify that the system operates properly .

Does the system operate properly ?

--

System OK

Go to Symptoms