GM Service Manual Online
For 1990-2009 cars only

Neither Blower Motor Nor Brake Lights Function

Step

Action

Value(s)

Yes

No

DEFINITION: This diagnosis checks for electrical failures back to the battery.

1

  1. Check that the connections at the Battery and at the Generator are clean and tight.
  2. Connect a test lamp between the Generator's negative (battery) terminal and ground.

Did the test lamp light?

--

Go to Step 9

Go to Step 2

2

  1. Locate the BLU fusible link at the Battery.
  2. Test the fusible link by pulling on the RED (2) wire attached to the fusible link.

Did the BLU fusible link wiring jacket stretch or break when pulled?

--

Go to Step 3

Go to Step 8

3

Check the RED (2) Battery Lead to the Generator for a short to ground.

Was a short to ground identified?

--

Go to Step 4

Go to Step 5

4

  1. Repair the short to ground on the RED (2) wire between the Battery and the Generator.
  2. Replace the BLU fusible link at the Battery.

Are the repairs complete?

--

Go to Engine Electrical Diagnostic System Check .

--

5

Inspect the Battery and Generator wiring for additions of aftermarket electrical loads.

Was an aftermarket electrical load identified?

--

Go to Step 6

Go to Step 7

6

  1. Remove the added aftermarket electrical load.
  2. Replace the BLU fusible link at the Battery.
  3. Perform any other repairs as may be required to return the wiring to normal.

Are the repairs complete?

--

Go to Engine Electrical Diagnostic System Check .

--

7

Replace the BLU fusible link at the Battery.

Are the repairs complete?

--

Go to Step 9

--

8

Locate and repair the open circuit in the RED (2) wire between fusible link Splice S119 and the Generator.

Are the repairs complete?

--

Go to Engine Electrical Diagnostic System Check .

--

9

Connect an test lamp between the Battery Junction Block studs and ground.

Does the test lamp light?

--

Go to Step 17

Go to Step 10

10

  1. Locate the BLU fusible link at the Generator.
  2. Test the fusible link by pulling on the RED (2) wire attached to the fusible link.

Did the BLU fusible link wiring jacket stretch or break when pulled?

--

Go to Step 11

Go to Step 11

11

Check the RED (2) wire to the Battery Junction Block for a short to ground.

Was a short to ground identified?

--

Go to Step 12

Go to Step 13

12

  1. Repair the short to ground on the RED (2) wire between the Generator and the Battery Junction Block.
  2. Replace the BLU fusible link at the Generator.

Are the repairs complete?

--

Go to Engine Electrical Diagnostic System Check .

--

13

Inspect the Battery Junction Block wiring for additions of aftermarket electrical loads.

Was an aftermarket electrical load identified?

--

Go to Step 14

Go to Step 15

14

  1. Remove the added aftermarket electrical load.
  2. Replace the BLU fusible link at the Generator.
  3. Perform any other repairs as may be required to return the wiring to normal.

Are the repairs complete?

--

Go to Engine Electrical Diagnostic System Check .

--

15

Replace the BLU fusible link at the Generator.

Are the repairs complete?

--

Go to Engine Electrical Diagnostic System Check .

--

16

Locate and repair the open circuit in the RED (2) wire between fusible link Splice S115 and the Battery Junction Block.

Are the repairs complete?

--

Go to Engine Electrical Diagnostic System Check .

--

17

Check that the connections at the Battery Junction Block are clean and tight.

Is the check complete?

--

Go to Engine Electrical Diagnostic System Check .

--