GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  1. Disconnect the LF window regulator motor.
  2. Probe with a test light, the LF window regulator motor harness connector between terminal A and terminal B.
  3. Turn the ignition switch on.
  4. Press the LF window switch up and down.

Is the test light on in both cases?

--

Go to Step 15

Go to Step 2

2

  1. Disconnect the LF window switch connector C1.
  2. With a DMM, check circuit 165 for continuity between the LF window switch harness connector C1 terminal D and the LF window regulator motor harness connector terminal A.

Is there continuity in circuit 165?

--

Go to Step 3

Go to Step 4

3

Using a test light, probe between the LF window switch harness connector C1 terminal D and ground.

Is the test light on?

--

Go to Step 5

Go to Step 6

4

Repair poor connection or open in circuit 165. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 16

--

5

Repair short to B+ on circuit 165. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 16

--

6

Using a test light, probe between B+ and the LF window switch harness connector C1 terminal D.

Is the test light on?

--

Go to Step 7

Go to Step 8

7

Repair short to ground in circuit 165. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 16

--

8

With a DMM, check circuit 164 for continuity between the LF window switch harness connector C1 terminal E and the LF window regulator motor harness connector terminal B.

Is there continuity in circuit 165?

--

Go to Step 10

Go to Step 9

9

Repair poor connection or open in circuit 164. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 16

--

10

Using a test light, probe between the LF window switch harness connector C1 terminal E and ground.

Is the test light on?

--

Go to Step 11

Go to Step 12

11

Repair short to B+ on circuit 164. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 16

--

12

Using a test light, probe between B+ and the LF window switch harness connector C1 terminal E.

Is the test light on?

--

Go to Step 13

Go to Step 14

13

Repair short to ground in circuit 164. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 16

--

14

Replace the LF window switch. Refer to Door Lock and Side Window and Outside Rearview Mirror Remote Control Switch Replacement .

Did you complete the repair?

--

Go to Step 16

--

15

Replace the LF window regulator. Refer to Front Side Door Window Regulator Motor Replacement .

Did you complete the repair?

--

Go to Step 16

--

16

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Diagnostic System Check - Door Systems