GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  1. Turn the ignition switch to the RUN position.
  2. Check the circuit breaker L1-L2 for an open.

Is the circuit breaker open?

--

Go to Step 7

Go to Step 2

2

  1. Turn the ignition switch to the LOCK position.
  2. Disconnect the LF window switch.
  3. Turn the ignition switch to the RUN position.
  4. Using a test light, backprobe between the LF window switch harness connector C1 terminal G and ground.

Does the test light illuminate?

--

Go to Step 3

Go to Step 6

3

Using a test light, backprobe between the LF widow switch harness connector C1 terminal G to terminal B.

Does the test light illuminate?

--

Go to Step 4

Go to Step 5

4

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

Has the repair been completed?

--

Go to Power Windows System Check

--

5

Repair a poor connection or an open in circuit 750 between C1 terminal B and G301.

Has the repair been completed?

--

Go to Power Windows System Check

--

6

Repair a poor connection or an open in circuit 143 between the fuse block terminal L2 and the LF window switch harness connector C1 terminal G.

Has the repair been completed?

--

Go to Power Windows System Check

--

7

Repair a short to ground in circuit 143.

Has the repair been completed?

--

Go to Power Windows System Check

--