GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Oldsmobile 🢒 1999 🢒 Eighty Eight 🢒 Body and Accessories 🢒 Horns 🢒 Horns Inoperative

Step

Action

Value(s)

Yes

No

1

Did you perform the Horns System Check?

--

Go to Step 2

Go to Horns System Check

2
  1. Disconnect the horn relay.
  2. Connect the test lamp between relay terminal 86 and ground.
  3. Connect the test lamp between relay terminal 87 and ground.

Does the test lamp light for both terminals?

--

Go to Step 4

Go to Step 3

3

Repair an open in CKT 1040 (ORN).

Is the repair complete?

--

Go to Horns System Check

--

4

Connect a fused jumper between relay terminal 87 and terminal 30.

Do the horns sound?

--

Go to Step 6

Go to Step 5

5
  1. Disconnect the left and right horns.
  2. Connect the fused jumper between relay terminal 87 and terminal 30.
  3. Connect the test lamp between horn connector terminal B and ground.

Does the test lamp light?

--

Go to Step 8

Go to Step 7

6
  1. Connect the test lamp between relay terminal 86 and terminal 85.
  2. Press the horn switch.

Does the test lamp light?

--

Go to Step 10

Go to Step 9

7

Repair an open in CKT 29 (DRK GRN).

Is the repair complete?

--

Go to Horns System Check

--

8
    • Connect the test lamp between horn connector terminal B and A.
    • Repeat this procedure for each horn.

Does the test lamp light?

--

Go to Step 12

Go to Step 11

9

Repair an open in CKT 28 (BLK).

Is the repair complete?

--

Go to Step 13

Go to Step 14

10

Replace the horn relay.

Is the repair complete?

--

Go to Horns System Check

--

11

Repair an open in CKT 1150 (BLK) or CKT 1550 (BLK).

Is the repair complete?

--

Go to Horns System Check

--

12

Replace the horns.

Is the repair complete?

--

Go to Horns System Check

--

13

Repair an open in CKT 28 (BLK).

Is the repair complete?

--

Go to Horns System Check

--

14

Replace the horn switch.

Is the repair complete?

--

Go to Horns System Check

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