Horn Upgrade --- DIY

They changed it to the horns and not the soft beep?

 

Great post, thanks!

For those people in the UK, the horns mentioned here are not available, so I used those available from Halfords (Google search Halfords Ring Low/High Note Car Horns Cat code: 134585-0).

One thing to note - these do have the requirement for an Earth cable, which I did not know until I was installing them! For now, I have jury-rigged some earthing, but I will need to go back in when I have bought a couple of "proper" ones!

Also, getting the plastic cover back on is REALLY fiddly, give yourself plenty of time, as this is the last operation, and can become annoying really quickly!

Andy

 

Finshed my horn upgrade today. Bought a used pair of horns from a Lexus SC400 off ebay and replace the bracket and the horn. Connections where plug and play with no mod or any additional grounding wire. Like what others have stated, it was easier to remove the bolt that holds the bracket by removing 2 12mm bolts and 5 or 6 plastic fasteners that holds the upper grill/bumper and pull the top part of the bumper/grill forward and wala, access to the bolt is much easier. Love the sound of my new horn.

 

Did mine lasst week.

I no longer honk in shame.

jp

 

THAT CRACKED ME UP!!!

Thanks for the laugh!

Alan

 

Just purchased a 2012 Prius 4 and joined the forum. I did the horn mod and used the Fiamm 72112 and 72102 purchased from Amazon, very nice cheap mod! thank you all for the great information and step by step install instructions.The Amazon web site said they would not fit a 2012 Prius but they do.

 

Interesting...
You have one of each?
I am just curious to know why you didn't get 2 of the same horn.
I can't find a difference between the two.

Thanks,
Alan

 

I installed one each of the low and high pitch, only thing I could relate it to would be more bandwidth...

The difference is dramatic, most definetily a worth while upgrade.

 

One is a low tone, one is a high tone. It's a more effective sound combination.

Most auto horns (at least on the vehicles I've owned) use a high-low combo.

 

When I looked it up on Amazon, the listings both said low and high tone for both horns depending on how you connected it.
When I checked FIAMM's site, it is clear that one is high and the other is low.

Alan

 

Yeah, there's a lot of confusion with the descriptions. Just order one each of the model numbers 72112 and 72102. I just ordered also. Couldn't stand the wimpy sound on my new PiP. Can't wait to install this weekend!

 

Going to order mine in the next day or two. Tired of the nearly non-existant horn of the factory install.

 

I tried out the horn last night on our v3 and it really wouldn't get much attention. I "ordered" one of these for my motorcycle (old BMW airhead) and it keeps the stock horn so you can still do the beep-beep but if you press the button for more than 1/4 or 1/2 second (selectable), it will then engage the 139db horn. I haven't received it yet as it is a Kick Starter project.

 

Hey, just wondering what model years have people tried this modification with... I'm thinking I want to try with my 2007 Prius but want to make sure the installation instructions are the same (or at least similar).

 

Should not be a problem. The biggest thing you would probably have to watch out for is fitment. There has to be enough physical room for the horn.

The wiring is usually pretty basic. You need a ground and power. Power come from pushing the "Pad" which closes the circuit on the relay, energizing the wire that is connected to the horn.

Worse case: there is not enough voltage which will require you to add a relay to tap directly into 12v's.

 

Just did the horn upgrade. Thanks so much for all the great advice here; really helped a lot and saved me the time of figuring it all out. From my experience:

* Definitely helped to take off the front emblem and to loosen the bumper cover. I tried without loosening the cover first and scratched up my arm a little bit.

* There wasn't a lot of slack in my wiring cables. One horn had the prongs on the bottom which made it easy to install, but the other had the connectors near the top which was tough. I rotated the horn enough to connect the power but not have risk of water entering the horn.

LOVE the new sound. Honks with authority now. This is a must-do and relatively straight-forward upgrade. Thanks again all.

 

I also wanted to replace the OEM horns on our Prii but then my mechanic dad advised me to try changing the frequencies of the two horns. By adjusting the one horn's tone just a little bit up and the other's a little down I managed to obtain a fairly decent sound from the horns. It sounds as if the different frequencies interpolate or reverberate and is a major improvement on the original sound.

 

Add another one to the horn replacement group I did my PIP in under 30 minutes and I took my time. It took me a minute to push in the release on the old horn to get the wire disconnected and that was the hardest part. Very very easy.

Ken

 

OK guys,

I did the horn upgrade on both my Prii, and the same thing happened. No, the horns work great, it's the 3 plastic pop rivets on top. They fall out...

I snapped them back in, but they will not hold and they are not broken. They just do not seem to expand enough to hold anymore.

Right now, I have a piece of electrical tape over them so they do not fall out again. Thoughts? ...

Thanks!

 

Here are a few pics of my horn upgrade. I used a Grover 1510 Emergency Horn (Same used on most fire trucks) a small compressor and a modified fire extinguisher for the tank. I installed a master cutout switch for the compressor and next to it another switch that lets me choose between the stock horns or the air horn. Both horns are triggered with the stock horn button. The horn is deafening up close and at freeway speeds it will startle anybody.....even with their windows up and radio cranked. It will definitely earn me a ticket if used carelessly.

The horn came in handy on our trip to Vegas on spring break. I was pinned between a semi and a guard rail on I-84 doing about 75mph and the truck driver decided that he wanted the left lane. Apparently he did not see me.....or didn't care.......because he came over in a hurry. I laid on the horn and he bolted back to his lane. I could see him in the mirror looking for a big rig and when he finally saw me he started to laugh and gave me the thumbs up.

People think its cool, stupid or a novelty but it has its safety purposes as well. I'd be road kill if I had to rely on the stock horn in that situation.