My 2024 GMC Sierra Is Acting Crazy, It Sprays Washer Fluid When I Press the Horn, But the Horn Doesn’t Work

This sounds unbelievable, but it's a true story.

A 2024 GMC Sierra pickup owner has a serious problem with his truck's horn and windshield wiper fluid. The connection between the two seems unfathomable at first, but the truth is even more surprising.

First, imagine getting in your new GMC Sierra pickup, driving to work, and you are at a stoplight. The driver in front of you is on his phone texting, and he doesn't notice the light is green, so he sits there, texting away. 

This alone would be annoying, but then something unexpected and bizarre happens when you hit your horn. 

So, you tap your horn to politely let the driver know the light is green and that they should go. However, when you touch the horn button in the center of the steering wheel, the horn does not work, and you see a small amount of windshield wiper fluid spraying on your windshield. 

You say, "What was that? Did I see my windshield washers spray? No, I must have been seeing things."

You can't believe it, so you press the horn button again, only for a more extended period, and the same thing happens. Only now, as you hold the button down, the horn still doesn't work, and your windshield is covered with wiper fluid. 

You do it again, and the same thing happens. Now you are playing with your horn, and you sit through the light as it turns red. Now you have an unhappy line of cars behind you. 

Sounds crazy, right? 

It happened to Joe Rodriguez. Whenever he presses the steering wheel horn button, the horn doesn't honk. But that's not the Problem; when he presses the horn, the windshield wiper fluid sprays on his windshield. 

For those who can't believe it, he shares a video clip of the strange windshield washer spraying phenomenon on the Chevy Silverado and GMC Sierra Owners Facebook page. 

Even stranger, this is not an isolated issue with Joe Rodriguez's GMC Sierra.

Other GMC Sierra owners have experienced the same strange thing with their pickups. 

A report from Repair Pal says it's not an isolated problem with the GMC Sierra.

They say, "Some GMC Sierra 1500 owners report experiencing issues where the windshield washer continuously sprays when the horn is pressed, indicating potential problems with the electrical system or wiring.” 

The strange phenomenon could be due to a faulty electrical system that causes the washer pump to receive power when the horn is activated. 

Additionally, some owners have reported that a short circuit in the wiring may lead to this unintended activation. 

Just Answer had a GMC owner ask the same question:

The owner says, "My horn is not going off, but the windshield washer motor won't stop. Nothing else was functioning, so I had to disconnect the battery. It's not leaking.” 

I'm looking for a voltmeter. It's a 2021 GMC Sierra 1500 Limited. I've only disconnected the battery. No, there's nothing else the mechanic should know before contacting me. I just got the windows tinted, and then this issue started.

The mechanic says, "Based on the symptoms described, there could be a faulty module or a weak battery. If you're under warranty, attempting a fix that results in damage could void your warranty. It would be advisable to have it towed to the dealership for repairs."

"Thank you for reaching out for assistance; I hope I provided the information you needed. Feel free to reply if you have any follow-up questions. If you found my answer helpful, please let me know so I can mark your question as complete."

So, what is the Problem with the GMC Sierra's horn?

This issue points towards potential problems with the electrical system or wiring in the vehicle. Specifically, it could be due to: 

• A faulty electrical system that erroneously sends power to the washer pump when the horn is activated.
• A short circuit in the wiring connected to the windshield washer pump led to unintentional activation.
• Issues with the multi-function switch (the lever controlling turn signals, wipers, and washer fluid), where the washer pump function might be stuck, causing continuous operation. 

What should GMC Sierra owners do if they encounter this Problem?

1. Inspect the wiring connected to the windshield washer pump for any loose connections or exposed wires.
2. Test the washer pump to determine if it's functioning correctly, as a faulty pump may need replacement.
3. Disconnect the washer pump connector and check for voltage to see if the washer pump motor is shorted internally.
4. Disconnect the multi-switch at the column and check if the issue persists, as a new multi-switch might be necessary.
5. Consult a mechanic or automotive technician to diagnose and repair the issue effectively, particularly if the Problem persists after these basic checks.
6. Addressing this Problem promptly is essential to avoid potential safety hazards or further electrical issues in your GMC Sierra.

Conclusion:

Joe Rodriguez's 2024 GMC Sierra is acting up, spraying windshield washer fluid when he presses the truck's horn. It's not an isolated issue. However, it isn't a widespread problem with the trucks. So, if you're a GMC Sierra owner and you stop at a light and hit your horn, don't be shocked at what you see. 

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Check out My GMC Sierra story: I Was Trailering a $130K Corvette With My GMC Sierra Denali at 1:00 AM When A Wheel Came Off, “It Was a Miracle That No One Got Hurt”

I am Denis Flierl, a Senior Torque News Reporter since 2012. My 30+ year tenure in the automotive industry, initially in a consulting role with every major car brand and later as a freelance journalist test-driving new vehicles, has equipped me with a wealth of knowledge. I specialize in reporting the latest automotive news, covering owner stories, and providing expert analysis, ensuring that you are always well-informed and up-to-date. Follow me on X @DenisFlierl, @WorldsCoolestRides, Facebook, and Instagram

Photo credit: Denis Flierl via Joe Rodriguez