Ok. Heres the way you do it:
But a train horn is a little unrealistic. Youll need a compressor, an air tank, and a large horn to accomplish that. You wont be able to hide all that sh*t.
And Im going to assume that the existing horn sounds more like a buzzer or beep than a real horn. This means that it draws very low amps and if you hook up a larger horn you will likely just blow a fuse. So I suggest doing it this way.
You will need:
3 18650 batteries
1 low tone modern automotive horn (link below)
https://www.amazon.com/Wolo-310-2T-Loud ... way&sr=8-3
1 4 pin Bosch style automotive relay (link below)
https://www.amazon.com/Bosch-0332019456 ... ay&sr=8-16
A soldering iron, electrical tape, a wire stripper and approx a 2-3 foot run of 16ga wire.
So you need to cut and strip a couple of 3 inch or so lengths of wire and solder them to connect your (fully charged) batteries as shown. Make the wire on each end at least 6 inches long to run it to your other components. This is a series connection. It will measure approx 12.6 Volts when its done correctly to fully charged batteries.
So connect the negative lead of your new battery pack directly to the negative terminal of the horn. Connect your positive lead to terminal 30 on the relay. The relay should be labeled but can always be identified because its the base of the "T" shape that every relay of this type makes on its terminals. Connect a new wire to terminal 87 of the relay (its the one that is oriented different from the rest...the TOP of the "T") and run it to the positive connection of the horn. The two remaining terminals on the relay (85 and 86) will need to be run to the EXISTING wires that connect to the horn of the target scooter. Disconnect the plug from the scooters horn and connect these wires in place of the horn. Polarity will not matter. The relay will function either way.
Now wrap your batteries in electrical tape real well so they dont short and start a fire and tape your relay to them and tape the horn down so the open end is not obstructed and youll probably want to point it straight at the driver for maximum sonic blast. Plug it in to the existing horn wires and hide this evil creation well so its not easily discovered. Then sit back and wait for the heart attack to happen. Call 911 if the target stops breathing or falls off the scooter.
But seriously, dont hurt anyone. This will be LOUD and frighten people both near and far.
And why did I bother putting the effort into explaining this ridiculous contraption? Because all of you scooter riding homies can use this information to put a loud horn on YOUR scooter to stay safe out in them streets. Drivers are not ready for scooters that do 30 or even 15 mph. Its f**king dangerous to be jammin down the street like this. The horn could save your life. Even if this guy kills his granny with this practical joke, hopefully more lives can be saved by applying this knowledge responsibly. And you can hook many other 12v devices up to your relay...not just a horn. Your imagination and the components amp draw is the limit. I dont have any more time to explain how a relay works. If youre curious just google it. Tons of info out there. And YES many people may wire their relays a little different. Or tell you to step voltage down from your main battery to achieve 12 volts. This is how I do it. Its simple and it works. Relays are awesome little tools to make a little switch control some powerful sh*t. Have fun. Have a good night. And dude...dont kill your grandma please....
- By Sc00tr