Horn Upgrade --- DIY

The meep-meep horn on my Prius V just didn't put out enough bark for traffic conditions here in Southern California. Searching around I came across info about replacement horns from a company called FIAMM. They sound significantly louder and deeper tone than the stock Toyota horns, kind of like horns from a Cadillac.

Here's a DIY on my install, and a video that gives a before and after comparison of the sound.

Note: Prius Plug-In owners, see the bottom of the post for special instructions.

Sound comparison:

This is a true plug-n-play installation, no wires need to be cut or soldered. Installation time is about 30 minutes, but I could probably do it again in 10 minutes now that I know all of the steps.

A few people have asked about relays. I installed mine with no extra relay added. A relay shouldn't be necessary because the current draw of these horns is very close to the stock horns, so you won't be putting any additional stress on the wiring system.

I started by buying FIAMM Freeway Blaster high and low note horns on Amazon, just $21+shipping for everything you need:

72102 FIAMM Freeway Blaster Horn High Tone
72112 FIAMM Freeway Blaster Horn Low Tone

-or-

74100 FIAMM El Grande Twin Horns (Red)*

*Update May, 2015: The Freeway Blaster horns have gone up in price since the original post. Several owners have reported that the less expensive 74100 Fiamm El Grande horns also work fine, come in a convenient twin horn package, cost less, and they're slightly smaller so they're a little easier to install. The El Grande horns are 128 dB while the Freeway Blaster are 130 dB.




Next was removal of the trim cover above the radiator. Three clips hold it on, pull up the clip with your fingernail, then wedge it off with a standard screwdriver. Note: If you have big hands and arms it might be necessary to take off the upper bumper clips for easier access.



There are two stock horns, located on either side of the radiator.





Next, remove the Toyota emblem from the front bumper so you have easy access to the horns. Just two screws hold it in, you'll need a stubby phillips (+)screwdriver because the area is pretty tight.








Unclip the stock power plugs (I recommend doing that before you loosen the horn because it's easier to get a grip on it). You'll need a 14mm wrench to get the old horns off, and a 10mm wrench to install the new horns.





Install the new horn using the stock bracket, bend it back a little because the new horn is bigger than the stock one. Clip on the supplied ground plug to either prong, then slide the other end over the horn mounting screw, contact with the metal mounting bracket provides the electrical ground to chassis. Tighten supplied mounting nut with a 10mm wrench. Clip on stock horn plug. Then do the other horn, same procedure. You might want to look at the horns through the front grill and adjust the angles. It's best to have the horn opening point down so no water accumulates inside.

Reinstall front emblem and trim cover. Here's what they look like from outside.



Enjoy

For Prius Plug-In owners:

1) You need to remove the fasteners that secure the top portion of the bumper cover to provide additional room. It doesn't matter if you have small hands, because...

2) You need to remove the speaker that warns pedestrians when you're at low speed. Only way to do that is at the bracket mount, which you can't get to unless you loosen the top of the bumper cover. If you don't do this, there's no way you're going to get to the right horn.

3) Because you have to do 1 and 2, I found it easier to remove the nut holding the bracket and horn, then remove them though the emblem hole, and then remove the horn from the bracket.

 

Mine is non-radar so I'm not sure what's different. The reason I removed the emblem is because the FIAMM horns are a little too big to squeeze through the gaps between the chassis and radiator. If the DRCC doesn't come out easily you can always just remove the front bumper.

 

My trollishness is greatly exaggerated

But you can bet if I ever experience unintended acceleration my horn will be heard.

 

If either of you guys want to meet up in Irvine I'd be happy to do the install. They're trying to organize a SoCal meet sometime soon, we could do the install at that meeting too. It's very quick and easy to do once you know the steps and have the tools ready.

 

Either way works, but removing the emblem only requires removal of 2 screws. Removing the upper bumper clip is 2 bolts plus the plastic clips. And, the emblem hole allows super easy access for your arm. If you've already done it you know the gap between the upper bumper and chassis is very narrow and has lots of sharp edges to attack your arm. But thanks for the link, I hadn't seen that video.