GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  1. Disconnect the inoperative horn.
  2. Connect a test lamp from horn connector CKT 29 terminal B to ground.
  3. Press the horn switch while observing the test lamp.

Does the test lamp light?

--

Go to Step 2

Go to Step 3

2

  1. Connect a test lamp from horn connector CKT 29 terminal B to CKT 1250/1350 terminal A.
  2. Press the horn switch while observing the test lamp.

Does the test lamp light?

--

Go to Step 4

Go to Step 5

3

  1. Test for a poor connection.
  2. Test for an open in CKT 29, between underhood accessory wiring junction block connector C3 terminal A7/B7 and the horn connector terminal B.
  3. If CKT 29 is OK, replace the underhood accessory wiring junction block. Relay/Fuse Center Replacement

Is the repair complete?

--

System OK

--

4

  1. Test for a poor connection at the horn.
  2. Replace the horn if the connection is good. Refer to Horn Replacement .

Is the repair complete?

--

System OK

--

5

  1. Test for a poor connection.
  2. If OK, repair the open in CKT 1250/1350, between the horn and G101/G102.

Is the repair complete?

--

System OK

--