GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Refer to Power Windows Operation . Did you review the Power Windows operation and perform the necessary inspections?

--

Go to Step 2

Go to Symptoms

2

Verify that only the left front power window is inoperative.

Does the window operate normally?

--

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

  1. Disconnect the left window regulator motor.
  2. Use a test lamp connected to ground in order to probe the UP directional drive circuit at the harness connector of the regulator motor to the left front window.
  3. Turn the ignition switch to the RUN position.
  4. Operate the left front window switch in the UP position.

Does the test lamp light ?

--

Go to Step 4

Go to Step 5

4

  1. Keep the regulator motor to the left front window disconnected.
  2. Use a test lamp connected to ground in order to probe the DOWN directional drive circuit at the harness connector of the regulator motor to the left front window.
  3. Turn the ignition switch to the RUN position.
  4. Operate the left front window switch in the DOWN position.

Does the test lamp light ?

--

Go to Step 6

Go to Step 9

5

  1. Disconnect the left front window switch.
  2. Use a Digital Multimeter (DMM) in order to test the UP directional drive circuit for continuity between the harness connectors for the switch and the regulator motor.

Is continuity in the circuit?

--

Go to Step 7

Go to Step 8

6

Replace the left front window regulator motor. Refer to Front Side Door Window Regulator Replacement .

Is the repair completed?

--

Go to Step 14

--

7

Use a DMM in order to test the DOWN directional drive circuit for a short to B+.

Is a short to B+ on the circuit?

--

Go to Step 12

Go to Step 13

8

Locate and repair a loose connection or an open in the UP directional drive circuit.

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 14

--

9

  1. Disconnect the left front window switch.
  2. Use a Digital MultiMeter (DMM) in order to test the DOWN directional drive circuit for continuity between the harness connectors for the switch and the regulator motor.

Is continuity in the circuit?

--

Go to Step 10

Go to Step 11

10

Use a DMM in order to test the UP directional drive circuit for a short to B+.

Is a short to B+ on the circuit?

--

Go to Step 12

Go to Step 13

11

Locate and repair a loose connection or an open in the DOWN directional drive circuit.

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 14

--

12

Repair a short to B+ on the directional drive circuit.

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 14

--

13

Replace the left front window switch. Refer to Front Side Door Window Switch Replacement .

Is the repair complete?

--

Go to Step 14

--

14

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3