Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.

"Train Horn" on Model S

Dec 26, 2018
Hi Folks,

A few weeks back, I installed a 4 trumpet air horn on my Model S. Why? Because the factory horn doesn't seem to be loud enough to get folks' attention when they are about to cause an accident.....and this has definitely solved that dilema.

I've received a bunch of PMs about it, so figured I'd share details here to avoid copying and pasting.

Below is a picture, followed by a parts list and explanation:


As you can see, this is all contained within the frunk of a Dual Motor car. The horns and tank are mounted to the bottom of the tub (no rattles or vibrations).

The kit is a Hornblasters Bullet kit with a 2 gallon tank. There is a smaller kit with a 1.5 gallon tank available as well.

I did buy two extra parts, a 90 degree 1/2" push-to-connect fitting for the tank to prevent hose kinks, and a 30a resettable circuit breaker so I can turn off the compressor if I want:

horn/compressor kit: Bullet 228H Air Horn Kit

air fitting: https://www.amazon.com/gp/product/B08734HVKT

circuit breaker: https://www.amazon.com/gp/product/B077CZJRN5

For activating the horn solenoid, I tapped into one of the factory horn connections (which are right in front of the frunk tub)- so the factory horn still works as well. I put a weatherproof connector on this, so if I want to kill the air horn I just pull that connector off.

I hard-wired it to the 12V battery right behind the frunk. I grounded it using the frunk bolt to the frame, which worked great. I put a 30a circuit breaker and a quick disconnect on the hot wire so I can just pull the whole frunk out if I want to remove it for taking to the Service Center or something. Since the car automatically recharges the 12V battery off of the main pack, it does not pose a risk of killing the battery....and if you don't have any leaks, it should only activate for 1 minute after a long horn blast at a maximum of 23 amps.

I also removed the frunk gasket to allow the air to travel and let the noise get out a bit more easily. I've driven in heavy rain, no water or dirt has gotten into the frunk without the gasket.

Functionally, this is loud as hell. I don't use it like a jackass to scare people, only as a quick "stop doing what you're doing" notice to those around me. It has been much more effective than the factory horn at getting attention for that. I get about 6-8 seconds of continuous blast, and the air compressor fills the tank back up in about 1 minute.

I'll post a video later, once I can get away from my densely populated area.


On a side note, you could absolutely tap into the factory air suspension tank, which is behind the 12V battery, rather than using a self contained tank/compressor. That would allow you to fit a bigger horn or just take up less space in the frunk. You'd just remove the Schroeder valve fitting on top and replace it with a 90 degree, 1/2" OD push-to-connect fitting and run the air hose down to the tub. With that said, you do that at your own risk. Not to say it'd break anything, but a Service Center wouldn't like seeing that the reserve tank was being used in that way.

Products we're discussing on TMC...

About Us

Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.

Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.