ColdFusion

iTrader: (2)

HI all, recently I got into a minor accident that ripped the front of my bumper off (I'll post a small photoessay of that later when it's completely fixed). Since taking off the front bumper, I figured I might as well tinker and upgrade a few things while everything's apart anyways. I won't say I was dissatisfied with the stock Lexus horns, but I was interested in Hella horns at the time so I figured why not try them out.

This is a guide on to how to wire Hella horns (SharpTones or SuperTones) to your Lexus IS250/350 (or any other Lexus for that matter, I assume most are similar). This is to a 2006 model, but I'm assuming this is similar up for all 2nd gen IS's.

I am not wiring this with the included Hella relay, simply because I don't want my engine bay looking sketchy as hell. I unfortunately do not know if not using the relay affects the loudness (I've heard it does, or sometimes the thickness of your ground wiring will).

You'll need:

Hella horns (duh)
An IS250/350 (double duh)
2 x .250" female spade quick-disconnect connectors, 10-12AWG
2 x 5/16" eyelet connectors, 10-12AWG
2 x 6" piece of 10-12AWG wiring

Tools:
Any ratcheting wrench with 12mm and 13mm heads
Soldering iron (if you wish)
Pliers
Heat shrink (if you wish)

First off, this entire job was done with the bumper off; I unfortunately don't know how to do this job by just removing the grille surround/insert. I followed @cyberscorp's headlight replacement guide to take off the bumper (https://www.clublexus.com/forums/is-...on-how-to.html).

The horns themselves. I chose the SharpTones over the SuperTones because I didn't like the weird frequencies of the SuperTones. The SharpTones are rated for 315Hz (low) and 415Hz (high) at 115dB(A), while the SuperTones are rated for 300Hz (low) and 500Hz (high) at 118dB(A).

Attachment 492950

Frankly, I'm not Richard Burns and the IS is far from a rally car, so I can do without the gaudy paint scheme. SubiMods wanted $15 more for the black surround version, so screw that. I got this set off Amazon for $53 and immediately started taking things apart.



With the surround off.



After a quick coat of Rustoleum primer + semi-gloss black, they look much better.



Let's first make your wiring connects. The purpose of this is that the Hella horns have two terminal connects on the back of the horn; one for positive, one for ground. Lexus horns directly connect ground from the horn body onto the frame via the mounting plate; Hella horns have it separate, so we need to make a piece that will attach the ground terminal to the frame of the car.

Gather your wiring pieces; I got all of this from a local hardware store for about $2.50.



Make sure your QD connectors will fit on the terminals - diameter is 1/4", or 0.250". It doesn't matter if it's insulated or not (I chose to remove the provided insulation so I could use my own heatshrink).



(Side note here: if at some point you need to change the direction of the terminals in relation to the plate, loosen the 13mm bolt seen on the back here then rotate the horn as you see fit).

Strip the wires, connect the eyelet connector to one end and the QD connector to the other. You can either attach them by soldering (my choice), crimping, or some other method - just make sure the electrical connection is solid. Here are my wires after soldering then heat shrinking.



My car in pieces. The two shell-shaped things up front are the horns. The horns are rated for 400Hz and 500Hz at an unknown loudness.





Before taking off the horn, disconnect the wire plug on the back side. There is a small button to depress, then just pull out.



Remove the mounting 12mm bolt at the top of the horn.



Mount the Hella horn using the same bolt, but this time screw on the eyelet connector side of your wire between the mounting plate and the frame.



On the backside of the horn, you will notice one of the connectors being marked with a blue dot. This will mark the ground terminal. Connect the other end of our ground wire to that terminal. Connect the Lexus stock plug over the other terminal.





And you're done!



Note the mounting locations are uneven, so if you have a grille that happens to be pretty see-through you may want to adjust the leveling.

Now test out your horns and install your bumper/front end back. Below are two videos comparing the sound differences.

Lexus stock:


Hella SharpTones:


(Note: After writing this DIY, I noticed if you wanted to match the Lexus stock frequency the most, you'd have to use the high frequency horns from both kits, 415Hz and 500Hz. You can then recycle the lower frequency horns for a different car. Or an ATV. Or your doorbell. Whatever floats your boat.)

Thanks for reading, and happy modding/installing! Feel free to ask any questions below, I'll do my best to answer them.

Zynthe

iTrader: (5)

Great write up.

Seems pretty simple. Cant wait to put these on my car.

DennisMik

Thanks for the how-to. I have a pair of Hella horns that I bought close to 10 years ago. They have been on 2 previous cars and are waiting for me to put them on the IS. I don't remember the model but they are probably the Supertone ones because they were red color, not the yellow like yours. I also painted mine black because the red color could be seen behind the grille.

drwafk

Nice write up, maybe its the video but the stock ones sound louder. I'm sure its different standing next to the car.

DennisMik

The video doesn't do the Hella horns justice. The volume level on the video is low. Hella horns are definitely louder. The Lexus horns are in the 65 - 70 DB range while the Hella horns are 115 DB.