If your 2023+ came with a single-tone horn, and, like me, you dislike how it sounds, here's a tutorial.
WARNING: I AM NOT LIABLE FOR WAREANTY LOSS THAT MIGHT RESULT FROM MODIFYING YOUR CAR'S WIRING. DO IT AT YOUR OWN RISK AND MAKE SURE YOU HAVE ENOUGH KNOWLEDGE TO CARRY IT OUT, OR HAVE A MORE EXPERIENCED FRIEND HELP YOU OUT.
There's another way to install a second horn described here: https://www.hrvforum.com/posts/485900/ , but for that method one would need to purchase the adaptor harness. I live in Brazil and that harness wasn't readily available here so I ran my own wiring and used a low tone horn I had lying around from a GM car I did the same install to - but that car had the low tone from the factory. Since I had purchased a pair back then, the high tone was stored for future use.
So, grab yourself a low tone snail style horn on Amazon. If you get a "chassis negative" horn it will make your life easier. Because it'll need only the positive wire, so one less wire to run.
Mount your low tone horn somewhere where it will be fastened to metal in the car's chassis. This will connect the horn to the negative pole of the battery using the chassis as a conductor. I found a place behind the grille towards the passenger side where there was a metal screw (it's mostly plastic fasteners in that area). It's easy to get to, just remove 5 plastic push pins and pull out the plastic trim surrounding the hood latch.
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The horn came with a metal strip that I then bent on the bench vise in a shape that would hold the horn in the correct position.
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I bought a cheap-ish online service manual (it sucks, don't recommend) and used it to find the horn relay, which is this one below.
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On the horn end of the wire, I soldered a 90 degree female spade connector I had lying around (pretty sure it came from the mortal remains of a washing machine 🤓). The wire I had available was unnecessarily thick, no need to use one of that gauge -- 18 AWG is plenty thick, even 20 AWG would do. Actually what's in the cars wiring is ridiculously thin.
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To test my dual horn setup I Jerry rigged the wire to the switched leg of the relay as below. The car actually spent a week and a half Jerry rigged like this 🤣, but I don't recommend doing what I did.
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After I verified it works I got some 3/16" corrugated electric hose/loom. 2ft will be enough. I got the type that is slit open so you can slide it over a wire that's already connected. I slid it over the wire and ran it under the plastic trim panel around the hood latch, then behind the driver's side headlight and down where a big-ish inline multi pin connector pair is. This is behind the driver side headlight and in front of the fuse box, but further down into the engine bay near the driver side "chassis rail".
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The horn positive wire from the relay was traced to the light green wire on the bottom row of that connector (see photo). I decided to cut the insulating tape that ties the loom together and roll it back, then pull this wire a little bit from within the loom, snip it with a pair of small wire snipping pliers, and remove about 1/4" insulation from both ends. I then spliced the new wire together with it using a solder seal / quick solder connector. Placed the wires inside and heated up the solder seal, and voilà .
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Wrapped the solder seal in electrical tape to protect it from the elements then taped the whole thing together the same way it was originally.
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Zip tying the new wire and its loom keeps the engine bay organized and tidy.
Now honk away at the dual tone horn! 🤓
WARNING: I AM NOT LIABLE FOR WAREANTY LOSS THAT MIGHT RESULT FROM MODIFYING YOUR CAR'S WIRING. DO IT AT YOUR OWN RISK AND MAKE SURE YOU HAVE ENOUGH KNOWLEDGE TO CARRY IT OUT, OR HAVE A MORE EXPERIENCED FRIEND HELP YOU OUT.
There's another way to install a second horn described here: https://www.hrvforum.com/posts/485900/ , but for that method one would need to purchase the adaptor harness. I live in Brazil and that harness wasn't readily available here so I ran my own wiring and used a low tone horn I had lying around from a GM car I did the same install to - but that car had the low tone from the factory. Since I had purchased a pair back then, the high tone was stored for future use.
So, grab yourself a low tone snail style horn on Amazon. If you get a "chassis negative" horn it will make your life easier. Because it'll need only the positive wire, so one less wire to run.
Mount your low tone horn somewhere where it will be fastened to metal in the car's chassis. This will connect the horn to the negative pole of the battery using the chassis as a conductor. I found a place behind the grille towards the passenger side where there was a metal screw (it's mostly plastic fasteners in that area). It's easy to get to, just remove 5 plastic push pins and pull out the plastic trim surrounding the hood latch.
The horn came with a metal strip that I then bent on the bench vise in a shape that would hold the horn in the correct position.
I bought a cheap-ish online service manual (it sucks, don't recommend) and used it to find the horn relay, which is this one below.
On the horn end of the wire, I soldered a 90 degree female spade connector I had lying around (pretty sure it came from the mortal remains of a washing machine 🤓). The wire I had available was unnecessarily thick, no need to use one of that gauge -- 18 AWG is plenty thick, even 20 AWG would do. Actually what's in the cars wiring is ridiculously thin.
To test my dual horn setup I Jerry rigged the wire to the switched leg of the relay as below. The car actually spent a week and a half Jerry rigged like this 🤣, but I don't recommend doing what I did.
After I verified it works I got some 3/16" corrugated electric hose/loom. 2ft will be enough. I got the type that is slit open so you can slide it over a wire that's already connected. I slid it over the wire and ran it under the plastic trim panel around the hood latch, then behind the driver's side headlight and down where a big-ish inline multi pin connector pair is. This is behind the driver side headlight and in front of the fuse box, but further down into the engine bay near the driver side "chassis rail".
The horn positive wire from the relay was traced to the light green wire on the bottom row of that connector (see photo). I decided to cut the insulating tape that ties the loom together and roll it back, then pull this wire a little bit from within the loom, snip it with a pair of small wire snipping pliers, and remove about 1/4" insulation from both ends. I then spliced the new wire together with it using a solder seal / quick solder connector. Placed the wires inside and heated up the solder seal, and voilà .
Wrapped the solder seal in electrical tape to protect it from the elements then taped the whole thing together the same way it was originally.
Zip tying the new wire and its loom keeps the engine bay organized and tidy.
Now honk away at the dual tone horn! 🤓
