Instructions On How To Install Hella "Super Tone" Horns (not air horns)
Detailed Instructions On How To Install
Hella "Super Tone" Horns (not air horns)
On Your MR2 1991->1995
NOTE: this proceedure assumes that you DO NOT have the
stock fog lights in place. It assumes that the stock
fog lights have either been removed alltogether or
have been replaced with some other aftermarket fog light
system such as the PIAA 1500.
WARNING: After installation of this horn set, when you plan to
test it, I would HIGHLY suggest that you have some type
of hearing protection before activating them as they
are extremely loud.
PARTS PURCHASED:
Hella Super Tone horn set purchased from Griots Garage
$69.95 + S&H
10 feet of#10 wire (RED) $3 at your local parts store
6 female quick connect terminals 12/10 gauge $3 at your local parts store
NOTE: for those that do not have a Black Panther battery, then you will
have to use a different terminal end to connect the #10 gauge wire
to the positive side of the battery.
As I do not have the terminal any longer, I have no way of checking
to see what type of terminal would be required. You will need to
figure this one thing out for yourself.
3M Double Sided foam tape either PN# 03609NA or 03410NA will do.
The 03609NA is the good stuff, it is their molding tape, which is
really stickey.
30 amp fuse
NOTE: due to the fact that fuses rarely ever blow (on my car) I just
solder the fuses in place.
You may, or may not want to do this, so if not then you can
purchase the proper fuse holder and wire it into the circuit.
TOOLS NEEDED:
10mm 1/4 drive socket
small 1/4 drive extension
1/4 socket drive
12mm 3/8 drive socket
6 inch 3/8 drive extension
3/8 socket drive
pair of scissors
pair of wire cutters
soldering iron
solder
needle nose pliers
shop light
Xacto knife
25/64 drill bit
1/2 drive electric drill
bottle of isopropyl alcohol to clean the area
that you want to stick the relay and wires down.
INSTRUCTIONS:
PREPING THE HORN MOUNTS:
First, the horns come with short straight pieces of metal strips
that have holes in each end. These are used to mount the horns.
On the set that I got there were three metal strips on each horn.
One end of these strips will need to have a 25/64 inch drill bit
hole drilled in them. 25/64 is .3906 thousandths.
I drilled each of the strips seperately, simply because it was
easier for me to do it that way with the tools that I currently
have.
After drilling out the holes then attach the strips to the horn
and make sure that you position the horn, ie.(rotate it properly)
so that the terminals point inwards towards each other.
What I mean here is that when both of the horns are properly in
place, then the terminals of the horns will be pointing inwards
such that they will be on the same side, (inward side) and
would be facing each other. I found that this was the best way
to position the horns so that the wires could easily be hooked up.
Start by opening the front hood and removing the inner plastic parameter
lining. In most cases, you will need to also remove the spare tire and
jack and handle kit to do this.
You will need to remove the NEG (negative) cable from the battery.
Remember that if you have stereo security codes set to remove them
first before disconnecting power.
When you are ready, then using a 10mm socket or wrench or
what ever size wrench it takes to loosen the NEG battery terminal
and loosen and remove the cable, and push it over out of the way
so that it does not accidently re-connect.
Now jack the front of the car up, and put it up on jack stands.
I use 2 by 1 inch thick oak slats on top of the jack stand to help
distribute the weight, so that the underside of the car is not bent
or damaged due to high pressure points. The slats are about a foot long.
Of course use the proper jacking points as outlined in the owners manual.
After the front of the car is up on jack stands then start removing the
front plastic under covers, remove the front most cover, and the second
one back.
Position a shop light so you can see what your doing.
Using the 1/4 drive socket extension, and 10mm socket, remove all of the
screws that hold on front two plastic undercovers.
Set these aside so they don't get in the way, and you don't lose anything.
In the center of the front compartment is a rubber grommet that can be
slit to allow the wire to go through it.
Figure out what type of terminal you will need to go on the wire end
to then fit on the positive side of the battery terminal.
Solder that terminal on one end of the #10 wire and then connect it to
the positive terminal of the battery post, and make sure that the
terminal is secure to the POSitive side of the battery.
Put a small slit in the center rubber grommet on the bottom of the
front compartment, and feed the rest of the wire down through the grommet.
Use the 3M super tape, and secure the wire several places running the wire
straight down to the rubber grommet is the most direct route and should
not get in the way of the spare tire when it is put back in place.
Now crawl under the front of the car and secure the wire in a path over
to the rail that runs under the front most plastic cover just below
the bottom of the radiator. This rail lends itself to easily stick the
relay that is supplied by Hella, on to the bottom side of the rail which
will keep the relay from getting wet and keep it out of the weather.
There is a relay supplied in the horn kit, the relay coil should have
a diode put across it in order to kill the counter EMF generated when
a voltage is applied to the coil. I use 1000 PIV diodes, a 1 amp will
work just fine. Since the counter EMF can get up to over 500 volts
then I usually double this value to find out what PIV
(peak inverse voltage) to use.
The diode is put across the coil (see the schematic printed on the relay)
in the reverse direction to the applied voltage.
If I remember correctly it is pins 85 and 86 so for example, if you
hook up the relay with the "control" voltage, not the power you are
switching, the control voltage is the lead from the stock horn wires.
So if you hook the stock horn wire to pin 85 then the cathode or the
marked side of the diode is put there.
The stock horn wire is the positive side or the + side. So the diode
negative or cathode (the silver band side) of the diode would go
to the positive side. The other side of the diode would go to the
negative or ground side of the relay coil which is then pin 86.
Again see the schematic printed on the body of the relay for the exact
pin numbers.
It does not matter which side of the relay coil is positive or negative
just pick one, and then make sure you apply the proper wire to that
terminal.
The main power leads go to pin 30 and pin 87 if memory serves. Again
look at the schematic that is drawn on the body of the relay.
Again, the main power leads it really doesn't matter much which is
the main input from the battery and which is the main output to the
horns, I did it as shown in the instructions that come with the horns
from Groit's Garage. The main power comes into pin 30 and goes out
to the horns on pin 87.
I typically put a non-polarized electrolitic cap across the contacts
what this does is act like a shock absorber, and helps the contacts
last longer. You can probaby get one over at Radio Shack or any
well stocked electronics store.
I use a 5mf or 10mf cap, which is very small, small enough to mount
on the side of the relay and use some quick glue and glue it on.
Of course with the non polar cap, it doesn't matter which lead goes
where.
Once the relay is ready to go then next find a spot to mount it
but don't stick it up in place just yet. I stuck it as I said earlier
in the rail center. This is a neat place to put it as it is up
resesed and out of the way. If it gets a little wet it won't matter
as the relay is fairly well sealed.
Position the main positive feed wire so that you can put your inline
fuse in also. I stuck my fuse directly in line in the main power lead
as I said, I like to solder my fuses in place, but you may want to
use a fuse holder. Most auto store and hardware stores have the
blade type fuse holders in a 25 or 30 amp rating.
I also placed the fuse so that it was tucked up in the rail to keep it
up out of the way.
Once you have found where you are going to position your fuse then
cut the main positive feed wire, and solder the fuse in place.
You may want to position the wire and the fuse so that it goes directly
to the position you are going to mount the relay, rather than cuting
a second piece of wire to go from the fuse to the relay pin.
If you decide to hook it up this way then on the other end of your
fuse holder then solder on a blade lug and then slide it on to
pin 30 of the relay, again, check the schematic printed on the relay
to make sure of the pin number.
Now you are ready to run to two pieces of wire out to the horns
to hook up the positive side of the horn connection.
NOTE: on the horn, the + side is marked by a silver rivet on the pin
and the negative side is marked by a copper rivet, at least that
is the way it was on my horn set. If you purchase from Griot's
Garage, then the instructions given hint at this being the case
by the position of the horns in the diagrams. But they do not
come right out and say that this one is positive and that one
is negative, which I wish they would have done.
NOTE: you will find it much easier to, as a last step, to actually
mount the horns in place. You will want to be able to get at
the back of the horn to press on the blade connector terminal.
Otherwise it is a real hassel to put the connectors on.
So back to the wires, measure off a piece of #10 wire and measure from
pin 87 of the relay down the rail and out to the horn. I found it
easiest to feed the wire straight back from the side of where the horn
mounts, as there is plenty of room to slide the wire just under the
radiator. There is a space there just to the side of where the horn
will be mounted that the wire can slide through. Or you can position
it several other ways to, I just did it the most direct route I could
find.
NOTE: on the terminals, I remove the little, yellow insulation part
on the end of the terminal, there really is no need to keep
them in place. The easiest way to remove them is to heat
the terminal up just a little with the soldering iron and
then just pull it off. Otherwise it will be very difficult
to remove, unless you heat it up first.
After you measure the wire then cut it and solder a female blade
terminal one end, and leave the end that goes to the relay open right
now, we will solder a terminal on it later.
After you solder the terminal on the one end of the wire then choose
one of the horns and press the terminal on the + side or the silver
rivet side of the two terminals on one of the horns, and then repeat
the operation for the other horn.
I had the terminal sides of the horns facing in towards the center
meaning that the horns were positioned so that the terminals were
on the inside, facing each other. This makes it a little easier to
position the wires on the horns. So when you tighten on the small
metal strips that are used for the brackets to mount them the
terminals will be within reach. And it makes it easier to position
and feed the wires through to the relay.
To run the ground wires, I simply found the very closest ground there
was, which is a small tapped hole that is just up from where the
horns mount. I scrapped away the paint from around the hole and
then found a couple of screws that fit, and made up a short grounding
wire, one end with a small loop terminal on it, and the other with
one of the female blade terminals on it.
The exact length of the wire can be easily measured. I think one was
about 4 inches long and the other on the drivers side was about
5 or 6 inches long.
NOTE: for these ground wires, there is a short piece of black wire
provided in the horn kit which is more than sufficient to work.
After you make up these ground wires, NOTE: they can be made of
#10 or #12 wire, simply due to the very short length involved.
then attach them one side to the horn NEG side (copper rivet)
and the other side screw up to the threaded hole in the frame.
Now you are ready to attach the horns up in place. To do this I used
the large bolt that was used to hold the stock fog lights up in place.
Using a 12mm socket and extension and 3/8 drive, then remove this bolt
and the small bracket, and then insert the bolt in the horn mounting
strips (the 25/64 hole you drilled) and then position it and screw the
bolt down.
NOTE: it is a little bit difficult to get a socket on this bolt but
it can be done if you position the horn properly.
After you bolt the horns up in place then check for position and then
tighten the bolt down.
You should have two wire ends of the #10 gauge wire from the two horns
that need to go to a female spade connector terminal and then to pin
87 of the relay. What I did was to use a pair of needle nose pliers
and spread open the end of the terminal that the wire goes into and
believe it or not two #10 gauge wires will just fit in and then you
can squeeze it closed enough to get it soldered in place.
Then once soldered, then press it on the relay on pin 87.
Now, you need to run either pin 85 or 86, depending on which one
you made NEGative, make up a short grounding wire for this terminal.
I ran mine over to a bolt that was close on the rail.
Make sure that when you ground this wire, that you scrape any paint
off so that you have a good ground connection.
Note that for the positive side of the coil on the relay, simply
tap into one of the wires, that is going to one of the stock horns.
It doesn't matter which one it is, I would suggest using the closer
one which would be the passengers side horn.
NOTE: that you can choose to leave the stock horns in place if you
wish, there would really be no need to go to the bother of
removing them, as there would be no problem to leave them in
place.
You can either tap off the wire, or you can disconnect one
and "Y" the connection if you wish.
NOTE: again, please check the schematic that is printed on the relay
to make sure that you have got the connections to the relay
correct.
Now to finish up the work with the relay, you will want to use some
3M super foam tape ie.(the molding tape) to stick the relay up in
the center of the rail. This will keep it up out of harms way.
NOTE: before you do this, make sure that you clean the area well
with some alcohol to make sure that the doubled sided foam tape
will stick well.
Then use some more 3M tape to stick the wires down where necessary.
Make sure that the wire is not going to get cut on any sharp edges.
WARNING: when you plan to test the horns, I would HIGHLY suggest that
you have some type of hearing protection as these horns
are extremely loud.