Mazda5 Horn Replacements

2012 Mazda5
Hi all, first time posting here and needing a little help.

The horn went out on my Mazda5 a little while ago and I'm not sure how to start. I've heard that it could be the horn itself, a fuse, or the button inside the steering wheel. For someone that's trying to do this at home in the garage, how would someone go about diagnosing this issue without tearing things apart?

  • What fuse controls the horn?
  • How do you get to the horn to change the little speaker out?
  • Talk to me like I'm 5, I have no idea what to do but I don't want to spend a crap ton of money doing this.

Thank you and there's mad respect for anyone that can answer this for me!


The 5 is FiftySix
2013 Mazda5 Sport AT
  • What fuse controls the horn?
In my base model Mazda 5 the horn fuse is in the engine compartment fuse block above the left front wheel. Pop off the black plastic cover and flip it over for fuse locations. It's a little confusing as the fuse location chart has variances depending on the options you may or may not have.

In my case, the horn fuse is where my finger is pointing in the photo below. (Must be logged in to see.)

12 Mazda5 Grand T
The stock horns on the Mazda 5 are dangerously weak. I recommend replacing them for your safety. I am using the Hella Supertones on my '12 and they have worked great for 3 years now. Much safer on the highway now. They have a japanese sound to them and are VERY loud. More of a "meep, meep", not a "honk".

Just be sure to crimp or solder all your connections and also use shrink tubing to seal them. My grounds were going bad after the first year, so I went back and cleaned the salt corrosion off them and put di-electric grease on them to keep the corrosion at bay. Much better now.

Basically, I just took the signal going to the old horns and ran it to a new relay to isolate the circuit. I ran a "+" lead from the fuse box by the battery and put an inline fuse on it to keep it legit. I had to fabricate some small brackets for the horns out of scrap I had and mounted them on the left and right frame rails aft of the crash bar behind the bumper. The wire runs thru the crash bar to the passenger side and powers the other horn. Then the circuit is grounded to the frame rail factory ground by the water pump.

I mounted the relay and grounded it to the frame just under the fuse box under the hood.

If you are not familiar with how relays work or are not comfortable with wiring, then find a mechanic that can do it for you.


2012 Mazda 5
Part of the issue is for some reason Mazda decided to only install high tone horns in many of their cars in the US market. Just adding a low tone makes it sound like a normal horn. Super tones are definitely nice. Incidentally they work just fine without the relay, and a splitter going from the factory wiring. There’s already a relay in the box for the horn. If I were talking about installing a much larger horn, or trumpets then I’d definitely use a relay.

I recently installed a set in my sister’s ‘08 to replace a mini air horn which crapped out. Used the Factory bracket with one extension from the horn box attached at the nut of the top horn.