GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Was the System Check performed?

--

Go to Step 2

Go to Horns System Check

2

  1. Turn ignition switch to OFF.
  2. Remove the horn relay.
  3. Connect a fused jumper across the horn relay terminals S10 and Q11.

Do the horns sound?

--

Go to Step 3

Go to Step 6

3

Connect a test lamp between the horn relay terminals S11 and ground.

Does the test lamp light?

--

Go to Step 4

Go to Power Distribution

4

  1. Connect a test lamp between the horn relay terminal Q10 and battery positive voltage.
  2. Press and hold the horn switch

Does the test lamp light?

--

Go to Step 5

Go to Step 11

5

Replace the horn relay.

Is the repair completed?

--

Go to Horns System Check

--

6

Connect a test lamp between the underhood fuse block terminal A12 or B12 (CKT 29) and ground.

Does the test lamp light?

--

Go to Step 8

Go to Step 7

7

Replace the underhood fuse block,

Is repair completed?

--

Go to Horns System Check

--

8

  1. Disconnect the RH horn.
  2. Connect a test lamp between the RH horn connector terminal A and B.

Does the test lamp light?

--

Go to Step 9

Go to Step 10

9

Replace horns.

Is repair completed?

--

Go to Horns System Check

--

10

Inspect G104 ground, if OK replace Ground Splice Pack G104.

Repair open in CKT 250 (BLK).

Is repair completed?

--

Go to Horns System Check

--

11

  1. Disconnect the underhood fuse block connector C2.
  2. Connect a test lamp between the Underhood Bussed Electrical Center (BEC) terminal D10 and battery (B+)
  3. Press and hold the horn switch.

Does the test lamp light?

--

Go to Step 7

Go to Step 12

12

  1. Disconnect C202.
  2. Connect a test lamp between connector C202 terminal B12 of the steering column side and battery positive voltage.
  3. Press and hold the horn switch.

Does the test lamp light?

--

Go to Step 13

--

13

Replace the horn switch.

Is repair completed?

--

Go to Horns System Check

--