Relay Switch for new horns

I'll try to answer the questions here:

First, the battery is located in the trunk, under the passenger side cubby. To get at it, lift up the floorboard flap thingy (as though you were goign to get the spare tire), then pull out the cover over the battery.

I believe there's also a way to disconnect the battery at the fuse box, but have never done that myself.

I can't see how replacing a horn will impair a vehicle in anyway, and know a few people on the boards have replaced the horn with something else.

There's really no such thing as "voiding the warrenty". Modifications you make may void parts of the warrenty, as they don't support modifications. But it's up to them to prove that the modification caused the part to fail. For example, if something goes wrong with the bladder or fuel pump or something, it would still fall under the warrenty. But if the relay for the new horn catches on fire and burns out the fusebox, well you're on your own.

 

The factory horns are powered through a relay so, unless your new horns pull more current, you shouldn't need to use the relay supplied with the new horns.

 

I put one of those Stebel horns on my motorcycle, that thing makes a racket! However, people do notice it. The Stebel is rated to draw 18A, so check to make sure the Prius horn relay can handle that current and if it can, just patch it in. If it can't use the horn wires to trigger your relay, get +12 from the engine compartment and ground the other side of the horn and you're up and running. Note that the horn has polarity markings near the terminals, I don't know how critical it is to obey them, but I did anyway.

 

<div class='quotetop'>QUOTE(ttabbal @ Oct 31 2006, 10:40 AM) [snapback]341236[/snapback]</div>

The last time I looked, our OEM horns were on a circuit with a 10A fuse. I expect that is the horns and not the relay.

- Tom

 

The same 10A fuse supplies both the horn and the horn relay.

 

<div class='quotetop'>QUOTE(FL Buckeye @ Nov 1 2006, 04:55 PM) [snapback]342245[/snapback]</div>

In that case, DO NOT wire the Stebel directly to the Prius horn wires. At best, you will blow the fuse. At worst, you could fry wiring. Just use the horn wires to trigger a new relay (the Stebel comes with one that will work) and connect a new lead to the 12V screw in the fuse panel. Be sure to use a fuse with it. I used a 30A ATC fuse holder with 12AWG wire for my motorcycle. All bought at the local auto parts store.

 

One of the first things I noticed when I got the Prius, was just how pathetic the horn sounded. Today, I went to my local Carquest and pick up a set of A/B horns from them. The horns have the Carquest name on the package, but the horns themselves are marked FIAMM.

It was a plug-and-play operation and both horns were replaced easily from the top, simply by removing the fasteners along the top edge of the grill molding. I followed these instructions: http://www.vfaq.net/mods/Horns.html

The grill material is very flexible and I used a pieced of dense foam to hold it open so I could work with both hands to mount the horn on the right side. Only had to modify (read: bend) the mounting bracket for right side horn slightly so it would clear the grill and the a/c condensor.

Sounds like a car now instead of a moped. It was a plug and play upgrade that took about 45 minutes.