Posts: 4
Joined: Sun Nov 18, 2018 4:12 pm
Delivery Date: 18 Nov 2018

Re: 2018 LEAF Horn Upgrade DIY

Sun Nov 18, 2018 4:55 pm

Personally I would not install additional horns to existing wiring without a 12 volt relay wired to the battery. Will soon be installing 3 new AC Delco horns wired to a relay, triggered by the stock horn wiring. Have done this to previous vehicles, including a motorcycle. The 3 different toned horns produce a diesel train sound. Loud and awesome. These are the same horns used on a 1996 Cadillac Deville. Each horn draws 3.5 amps (11 amps total). Instead of accessing stock horn, hope to identify and trace wiring from fuse or horn ring? Place a switch at that location to be able to switch between stock and the 3 new horns. This way when inflating the tires I can switch it to stock and not go deaf when reaching the proper psi. I have yet to have to inflate tires but read that when reaching proper psi the horn is triggered. The horns are AC Delco D1922C, D1923C, and D1925C, which produce a F- low, D- super low, and A- high note. Available at any online auto or amazon or Walmart. If you love an attention getting train sound that takes up little room, and draws very little power, this is it! Will provide details on install after completion.

Posts: 1
Joined: Wed Dec 05, 2018 7:06 am
Delivery Date: 05 Dec 2018
Leaf Number: 310920

Re: 2018 LEAF Horn Upgrade DIY

Sun Dec 16, 2018 6:53 pm

Hey OrientExpress, thanks for the great write up and photos. My girlfriend was kind enough to let me perform this upgrade on her new leaf. Only having the vehicle for a few weeks, I had too many close calls when driving with the embarrassing horn.

I opted to go about the mounting in a slightly different location, but was able to take a lot of great ideas from contributors here to put together a really solid upgrade. I'll include the links for the stuff I purchased on amazon. Generally I didn't have too many of the electrical kits, so I ended up spending a lot more on those items, but I'm glad I have them now.

Horn - ... UTF8&psc=1
Wire - ... UTF8&psc=1
Connectors - ... UTF8&psc=1
Wire sleeve - ... UTF8&psc=1
Shrink tube - ... UTF8&psc=1

I purchased these plastic tools (plastic snap tool is metal) for another project. I can say they have come in handy for projects like this. I would highly recommend them to anyone looking to work on their car.

Tools - ... UTF8&psc=1

I can't figure out how to post my images from my fix, but I'll try to work that out. Thanks again everyone!

Posts: 1
Joined: Wed Dec 26, 2018 5:23 pm
Delivery Date: 27 Dec 2018
Leaf Number: 304895

Re: 2018 LEAF Horn Upgrade DIY

Wed Dec 26, 2018 5:34 pm

Hello. I just recently purchased a 2018 Leaf and joined this forum. I found that the stock horn was anemic and appreciate your write up as it provided a lot of useful information. There is one correction that needs to be made. A pair of Hella Super tone horns draw 14 amps, which is far more than 18 gauge wire can support. Hella recommends that we install a relay, which is how I did it. The main power from source to the relay should be 12 gauge and have a 16 amp fuse per Hella. The positive wire from the relay to the horns can be 14 gauge. Since I bought a roll of 12 gauge for this job I used it. I also used the same gauge to ground the horns to the chassis. There are two more spades on the relay and these get connected to the original horn wires. 18 gauge is sufficient for this as it merely provides a signal to the relay.

You might be able to get away with running 18 gauge from the original horn connectors to the new horns if your honks are short but the horns will not be able to draw the current they are designed for and will not be as loud. There is a risk of overheating the conductors and a failure in the harness would be a real drag.

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Leaf Number: 2331
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Re: 2018 LEAF Horn Upgrade DIY

Wed Dec 26, 2018 5:42 pm

I’ve been installing these Hellas since 2011 in LEAFs and never had an issue.

You are more that welcome to over think the install, but my method is solid, and and proven in lots of LEAFS both gen 1 and 2 that have them installed as shown. The worst that can happen is if the wiring is installed without regard to a floating or chassis ground, and that will just pop the fuse.
2018 LEAF SL
Gun Metalic
Delivery April 10 2018

Prior LEAF:
2014 LEAF SV
Ocean Blue
Delivery May 23 2014
50,000+ miles - all 12 bars - Same range as new - No warranty issues ever!

Posts: 3
Joined: Sat Mar 30, 2019 3:11 pm
Delivery Date: 30 Mar 2018
Leaf Number: 306567

Re: 2018 LEAF Horn Upgrade DIY

Sat Mar 30, 2019 3:45 pm

Thanks so much for this great instructions. I used them to install a new horn in my 2018 (the original horn is truly pathetic) and found a way to do this without having to install additional wiring or open any additional compartments under the hood. Here's what I did;

1- Bought a Wolo Bad Boy horn for the install. These are available online or at Harbor Freight for about $30. Not the loudest aftermarket horn around but plenty loud enough for my purposes (and WAY louder than the original).


2- Once the wheel well liner was off, I disconnected the wiring to the original horn, per the instructions above (BTW, the original horn can be removed if you have a small 12mm wrench- you just need to reach up and feel around for the single bolt that attaches it, and then unbolt it).

3- There is a small inverted plastic well right below the horn area. I drilled a hole through that well from below, put a single washer over the bolt that comes with the Bad Boy horn, and inserted that bolt through the hole.


4- Attach the horn wires from the Leaf to the new horn (brown to positive, black to negative) . The connectors are the same size as on the old horn, so they fit perfectly.

5- Put 3 washers on the bolt so the horn will set level on the plastic well. Put the nut that comes with the bolt horn into the little metal connector flange on the horn, and then screw the bolt into the nut and tighten.


6- That's it! Now just follow the original instructions for re-attaching the wheel well liner and putting the wheel/tire back on.

Can't tell you how great it is to have a horn that actually gets people's attention. Once again, thank you for posting these instructions!

Posts: 3
Joined: Sat Mar 30, 2019 3:11 pm
Delivery Date: 30 Mar 2018
Leaf Number: 306567

Re: 2018 LEAF Horn Upgrade DIY

Sat Mar 30, 2019 7:45 pm

A postscript to the above- the Bad Boy horn lived up to it's name and blew the horn fuse. I upped the fuse from a 10A to a 15A, but if it happens again, I'm afraid I'll have to install a relay.

Posts: 17
Joined: Tue Sep 25, 2018 10:14 am
Delivery Date: 24 Sep 2018
Leaf Number: 302391
Location: Northern CA

Re: 2018 LEAF Horn Upgrade DIY

Sun Mar 31, 2019 6:32 pm

tomseid wrote:A postscript to the above- the Bad Boy horn lived up to it's name and blew the horn fuse. I upped the fuse from a 10A to a 15A, but if it happens again, I'm afraid I'll have to install a relay.
How much honking did you have to do to blow the fuse?

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Volt: 2012-2018

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Joined: Fri Jan 20, 2017 9:23 pm
Delivery Date: 21 Jan 2017
Leaf Number: 424033
Location: Seattle

Re: 2018 LEAF Horn Upgrade DIY

Tue Apr 02, 2019 7:13 am

the stock wires were not terribly large when i upgraded my horn, certainly not 14 AWG that a 15 amp fuse would require.. careful not to melt/damage anything in your harness! the 'correct' fix would be to wire the stock horn wires to a relay that triggers a new fused circuit from the battery, but that gets messy in it's own way.

2013 Leaf SL Premium
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Re: 2018 LEAF Horn Upgrade DIY

Tue Apr 09, 2019 7:53 pm

My horn update today took less than a hour. Only about half of the front section of the fender liner needed to be removed.
Once access to the original horn is gained, one just needs to remove the 10 mm nut and lock washer. The replacement horn
that was used is available from Pep Boys (Wolo, 385-2T) for $22. That horn draws about four amps and has the same size spade
connectors as the original horn. The physical size of the 385-2T is just a little bigger, but fits nicely on the original bracket. A couple
of zip-ties to a strong rigid mount near the horn were used to minimize the vibrations of the original cantilevered horn bracket.
The sound volume from the replacement horn is about typical of most American vehicles.
#1 Leaf SL MY 9/13: 76K miles, 47 Ahrs, 5.0 miles/kWh (average), Hx=70, SOH=73, L2 - 100% > 1000, temp < 95F, (DOD) > 20 Ahrs
#2 Leaf SL MY 12/18: 10.3K miles, SOH 109Ahrs/115Ahrs, 5.2 miles/kWh (average), DOD > 20%, temp < 105F

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Re: 2018 LEAF Horn Upgrade DIY

Wed Apr 10, 2019 9:39 am

I also installed the Harborfreight "Bad Boy". It is loud and annoying enough, and is small. The only issues I have had with it is when it is raining VERY hard, or when the temps go down to single digits, it only make a tiny vibration noise for a while.

PS - I would try to not mount the horn inside the engine compartment. The sound will be muffled in there... Best is near the bumper or nose of the car...???

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