Miata Mailing List: June 1995, Message #72
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   From: guerrero@dsd.northrop.com (Guerrero Joe F.)
Subject: Re: How/where to mount Hella horn set?
   Date: Thu, 1 Jun 1995 20:04:50 -0400

> 
> I hear there is a FAQ out there on how and where to
> mount the Hella horn set... can anyone direct me or
> for that matter give me some pointers ?
> 
> Thanks,
> Rob - '93 Black SE
> 
> 
> 
Rob,
  What were you thinking when you sent this message?  The Hella
Horn Install FAQ was discussed on March 5 of 1995.  In fact
horn installation was a hot topic that day.  You should have
checked the miata.archives before posting.  All you needed
to do was download the last 4 years of archives to your hard
drive (What's 30 Meg of hard drive space anyways) and search 
for the words (Horn, horn, Install, install, Hella, hella...)
There's probably only 1000 instances of each of these words.
Wouldn't take any time at all to read every single post referring
to horns... ;)

Since I too am interested in installing Hella horns, if I
ever get around to it, I just happened to save the following
messages since they were important to me.  Hope they help
and THANK YOU to the original posters for taking the risk
of being flamed for discussing a topic that has been discussed
over and over in the past four years. 

Below are previously posted messages regarding horn installation,
If you are an expert in Miata horn installation or have participated
in any prior discussions regarding horns, or have all of the Miata
archives dating back from 1991 readily available, now would be the
appropriate time to hit the delete key. 

-----------WARNING: Previously posted message follows-------------------
From: Meoughta@aol.com
Subject: Hella Horns: Install Details
Date: Sun, 5 Mar 1995 17:37:26 -0500

Hey Guys and Gals,

I received a number of requests for installation details for the Hella Air
Horns, so in my best technical writing, here we go :^o

Convention:

I am going to refer to left/right as if you were standing in front of the car
looking into the engine compartment.  So, left is the passenger side.

Hardware Requirements:

- Hella airhorn kit
- About 10 female spade connectors for #14 wire (blue)
- About 10 feet of #14 wire
- A 30 amp block fuse
- Electrical tape

Hardware Mounting:

1.  Remove the large shroud under the engine and the smaller shroud that
connects to the bottom of the bumper.  This allows access to the area between
the front bumper and the radiator.

2.  Remove the old wimpy horn and mounting bracket to the left of the hood
latch.

3.  Just to the left of the hood latch's left mounting bolt, there is a
horizontal hole in the sheet metal.  Mount the air horn compressor here.  It
should fit perfectly in relation to the hood latch hardware. 

4.  Use the old wimpy horn mounting bolt to mount the Hella horn relay.

5.  Just to the right of the hood latch, locate the air bag deployment sensor
(a strangely shaped, black plastic covered box thing).  Just to the right of
that, there is a threaded horizontal hole.  Bend the "Z" shaped horn bracket
provided into an "L" shape and mount one of the horns at this point.  Locate
the horn between the bumper and radiator, and face the horn towards the right
front (remember my direction convention).  The threading in this hole fits
the mounting bolt provided with the kit.

6.  Locate the black structural support that runs in front of the hood latch
and attaches to the top of the front bumper.  This support has nine holes
punched in it.  Drill out the fourth hole from the right to fit the horn mount
ing bolt and bolt the other horn to it.  Mount this horn parallel to the
other.

7.  Cut the air tubing to fit and install.  Note: I installed the tubing from
the compressor to the "Y" connector at the top of the "Y".  It seemed to give
a better tubing route to the horns.

Wiring:

Refer to wiring diagram #2 provided with the horn kit.

1.  Connect the old horn wire to the new horn relay at terminal 86.

2.  Cut and run a suitable length of #14 wire from the new horn relay
terminal 87 to the air horn compressor "+" terminal.

3.  Run a length of #14 wire from the horn compressor "-" terminal to a
grounding point.  Also run a wire from the new horn relay terminal 85 to
ground.  Note:  I mounted a grounding lug using the new relay mounting bolt.

4.  Locate the engine compartment fuse box on the left side of the engine
compartment.  The windshield washer fluid bottle is attached to it.  If you
unbolt the fuse box and turn it over (carefully, so that none of the wires
are stressed), you will see a large black wire lugged to a bolt.  This is the
+12V source from the battery.

5.  From the top of the fuse box, locate the spare fuse slot.  My box was
labeled from the top:  HEAD 30A, INJ 30A, MAIN 80A, BTN 40A, ,
COOLING FAN 30A.  The spare is at the large X.  Attach a female spade
connector to approximately 5 feet of #14 wire and connect to the outlet side
of the spare fuse slot.  This is the terminal toward the wheel well on the
bottom of the terminal box.

6.  Run this power supply wire to the new horn relay and connect to terminal 3
0.  Use electrical tape to secure the power supply wire to existing wire
harnesses in the engine compartment.  Also, where the wire runs through
openings in the sheet metal, thread it through some of the spare air tubing
to protect from rubbing through the insulation.  Be careful to route this
wire away from hot or moving parts.

7.  Remount the engine compartment fuse box.  Install the 30A fuse in the
spare slot, and test the horn.

Some Important Notes:

These mounting instructions apply to my 93B with AC but no ABS.  I have never
looked under the hood of any other Miata (yet), but imagine it can't be THAT
different.  If the spare fuse slot is taken, you can at least get power from
the fuse box supply wire, but be sure to install an in-line fuse.  You may be
able to find better mounting locations once you get up into the area between
the radiator and the front bumper, but for my Miata, the mountings noted
above are pretty darned good!

Good Luck!

Pete and Davos

-----------WARNING: Previously posted message follows-------------------
From: LSAPEX@aol.com
Subject: Air Horns Power
Date: Sun, 5 Mar 1995 17:21:22 -0500

I've installed many sets of Hella air horns into Miatas, and came up with a
fairly easy system.
I connect to the blue connector coming out of the wiring harness at the left
front fender (It's a power source for timing lights etc. because there is no
battery to hook to in the engine compartment) for power (30 on the relay).
You can open the wiring harness at this point and find the green and red wire
for the horn, use the end coming from the fire wall to switch the relay (85)
The end of the green and red wire going to the horn goes to 87. 86 is a ground