Horn Relay

Replace the horn relay in the underhood fuse block to restore horn operation.

Warnings

Tools required

Parts

• Horn relay × 1 — Use OEM specification - GM Part Number may vary by build date

Preparation

1. Park vehicle on level surface and engage parking brake
2. Turn off vehicle and remove key fob from interior
3. Open hood and secure with prop rod
4. Allow engine bay to cool if vehicle was recently driven
5. Locate the underhood fuse block on the driver's side of the engine compartment

Procedure

1. 1

   Disconnect 12V battery negative terminal
   Using a 10mm socket, loosen the negative (-) terminal clamp bolt on the 12V auxiliary battery (located in rear cargo area or under hood depending on configuration). Remove the cable from the terminal and secure away from battery post. Wait 2 minutes for electrical system to fully discharge.
   Torque spec

   Battery Terminal Bolts6 Nm (4 lb-ft)
2. 2

   Access underhood fuse block
   Locate the underhood fuse block on the driver's side of the engine bay. Release the cover tabs by pressing or lifting as designed and remove the fuse block cover. Inspect the underside of the cover for the fuse/relay diagram to identify horn relay location.
3. 3

   Identify horn relay
   Using the diagram on the fuse block cover or owner's manual, locate the horn relay in the fuse block. The horn relay is typically labeled and positioned in the relay section of the fuse block. Note the orientation of the relay before removal.
4. 4

   Remove old horn relay
   Grasp the horn relay firmly and pull straight up to remove it from the socket. If difficult to grip, use a relay puller tool or needle-nose pliers with gentle pressure. Avoid rocking side-to-side excessively as this can damage the socket terminals. Inspect the relay socket terminals for corrosion or damage.
5. 5

   Install new horn relay
   Align the new horn relay pins with the socket, ensuring correct orientation matching the original installation position. Push the relay straight down into the socket until it is fully seated and flush with surrounding relays. The relay should click into place and sit firmly without wobbling.
6. 6

   Reinstall fuse block cover
   Position the fuse block cover over the fuse block, ensuring no wires are pinched. Press down on all edges until cover tabs click securely into place. Verify cover is fully seated around entire perimeter.
7. 7

   Reconnect 12V battery
   Reconnect the negative (-) cable to the 12V battery terminal. Tighten the terminal clamp bolt to specification using a 10mm socket. Ensure connection is secure but do not overtighten.
   Torque spec

   Battery Terminal Bolts6 Nm (4 lb-ft)

Reassembly

1. Ensure fuse block cover is properly secured and all tabs are engaged
2. Verify no tools or parts are left in engine compartment
3. Close hood securely

Verification

• Turn vehicle to ON/RUN position without starting (press brake and push start button without foot on brake)
• Press horn button on steering wheel and verify horn sounds properly
• Test horn from both sides of steering wheel if equipped with dual horn switches
• Verify no warning lights appear on instrument cluster related to electrical system
• Reset clock and radio presets as needed

Related trouble codes on this vehicle

Codes that commonly send this job to the bay — tap one for symptoms, causes, and diagnostic steps.

Chasing one of these codes and not sure which part is guilty? Ask a master mechanic about YOUR car →

More procedures for this vehicle