For 1990-2009 cars

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---

• | Sticking contacts in the horn relay or the horn pad may cause this condition.

• | The wiring shorted to ground may energize the horn relay.

One of the above malfunctions may cause the windings to open on most horns. Before you replace the horns with the open windings, ensure that none of the above conditions exist. The horn windings may open again.

1 | Exchange the horn relay with a known good relay from the underhood wiring harness junction block. Does the horn continue to sound? | -- | Go to Step 2 | Go to Step 3
2 | Disconnect connector C3 from the underhood wiring harness junction block. Does the horn continue to sound? | -- | Go to Step 9 | Go to Step 4
3 | Replace the faulty relay. Is the repair complete? | -- | Go to Diagnostic System Check - Horns | --
4 |

1. Reconnect connector C3 to the underhood wiring harness junction block.
2. Disconnect connector C2 of the turn/headlamp switch assembly.

Does the horn continue to sound?

--

Go to Step 5

Go to Step 6

5 | Disconnect the body control module connector C1. Does the horn continue to sound? | -- | Go to Step 8 | Go to Step 7
6 | Repair a short to ground in the horn switch. Refer to Multifunction Turn Signal Lever Replacement - On Vehicle in Steering Wheel and Column/Standard. Is the repair complete? | -- | Go to Diagnostic System Check - Horns | --
7 | Replace the body control module. Is the repair complete? | -- | Go to Diagnostic System Check - Horns | --
8 | Repair the short to ground in CKT 28 between the underhood wiring harness junction block and the body control module. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check - Horns | --
9 | Disconnect connector C2 from the underhood wiring harness junction block. Does the horn continue to sound? | -- | Go to Step 10 | Go to Step 11
10 | Repair the short to positive battery voltage in CKT 29, between the underhood wiring harness junction block and the horn assembly. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check - Horns | --
11 | Replace the underhood wiring harness junction block. Refer to Underhood Fuse Block Replacement in Engine Electrical. Is the repair complete? | -- | Go to Diagnostic System Check - Horns | --