GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Disconnect the combination switch connector.

Did the horn stop?

--

Go to Step 4

Go to Step 2

2

Remove the horn relay.

Did the horn stop?

--

Go to Step 3

Go to Step 5

3

Connect a DMM from the horn relay connector PIN 85 in CKT 170 (GRN/RED) relay center 2 and ground.

Is there continuity?

--

Go to Step 6

Go to Step 7

4

Replace the horn switch.

Is the repair complete?

--

System OK

--

5

Locate and repair the short to voltage in CKT 29 (DK GRN) between the relay center 2 and the horn(s).

Is the repair complete?

--

System OK

--

6

Locate and repair the short to ground in CKT 170 (GRN/RED) between relay center 2 and the horn(s).

Is the repair complete?

--

System OK

--

7

Replace the horn relay.

Is the repair complete?

--

System OK

--