GM Service Manual Online
For 1990-2009 cars only

Step

Action

Normal Result(s)

Abnormal Result(s)*

1

  1. Start the vehicle.
  2. Turn the blower switch to the HIGH position
  3. Turn the A/C on.

A/C compressor clutch engages. Cold air comes from air vents.

Air from vents does not get cold.

2

Turn the A/C, leave the blower on High.

A/C compressor clutch disengages. Cool air from vents warm after a few minutes.

Air remains cool coming from vents.

* Refer to the appropriate symptom diagnostic table for the applicable abnormal result.