|Cadillac 4-Note Horns
for my Volvo 240
|UPDATED: February 13, 2019 CONTACT|
M A I N S
<<< My Volvo 240 originally came with these horns behind the grill. They were just ok. Nothing special.
|I had been thinking about doing this
upgrade for a while and I finally pulled the
trigger. I found a set of four (4-note) horns
online and bought them.
These are known as Cadillac 4-Note Horns. I don't know the specific years, but these horns were equipped in most Cadillacs up to about 1980 and in the Cadillac DeVille until about 1985 (after which the Deville was downsized). They also came in Cadillac Fleetwoods and large Buicks until about 1995. Also supposedly in Oldsmobile Toronados until about 1985.
These horns are made of steel and plastic. Much earlier Cadillacs and large GMs got 4-note horns going back into the 1950's or before, but these much earlier horns were all metal and may have different markings.
The four horns are each tuned to a separate specific note: A, C, D and F. Later cars with only 2 horns reportedly got only notes A and F. After the 4-note horns were discontinued, all GM cars came equipped with only two horns.
Each horn has the note A, C, D or F embossed as
shown here. The round portion of these horns is
stamped steel and the trumpet section is molded
The horns I found have two-wire
connectors (power and ground). These are
models horns. When shopping for horns, be aware
that there are some
(see lower photo) that have only one wire to each
horn. That one wire is the power wire. These are reportedly earlier horns. On
the one-wire horns
the ground is completed through the mounting
bracket. I don't think this makes any difference
in how they sound. Just be aware in case you have
If you're doing this to a Volvo 240, you should know
these cars don't have
a normal horn activation circuit. The 240
has YELLOW and BLACK wires as shown here. The yellow
wire is the power wire and it has 12 volts whenever the
key is in the ON #1 or ON #2 position. The horn is then activated
through the black ground wire, which is
triggered by the horn button on the steering wheel.
The Volvo 240 does NOT use a relay in the horn circuit. In order to make these 4-note horns work correctly, a relay is being added to change how the horns are powered and triggered.
If you're installing these horns in a non-Volvo with a normal horn circuit, I would still advise installing a relay circuit if you don't have one. These horns reportedly draw about 5 amps each and they'll always work better when more direct full battery voltage is available.
Here's a diagram I made. This is how I made my relay circuit.
I used TWO relays. Each relay powers two horns. I suspect that ONE relay is enough for all four horns, but I did it this way after seeing the majority of other installations doing it this way.
Volvo 240 horn circuits are different from normal cars. The horn switch in a 240 is a ground circuit, instead of a normal car, which is a power circuit. So if you have a 240, look for the two-wire harness going to your horns and you'll find the yellow and black wires shown below.
straightened the mounting brackets on all four horns
using my bench vise and big pliers. I
also ended up cutting about an inch off the end of each
bracket. That's up to you on if this helps you
I've heard it may be possible to mount these so they're too stiff or too rigid. I don't know if that's true, but certainly mounting them so they can't freely vibrate can negatively affect the sound. Keep this in mind if you're cutting down the brackets or changing how rigid they will be mounted.
When mounting these, keep in mind that the trumpet openings should be pointed downward so they don't collect water. Also I have read that the best sound will be from horns that are mounted close together and, if possible, pointing all the same direction. These horns vibrate a lot when sounding, so you should mount them so they are not touching each other or touching any parts of the car (except of course where the brackets are mounted).
Here's a photo ABOVE of the horns installed behind the front grill in my 240. After I was done, I changed my mind about this location and ripped them out.
I didn't like how much air these blocked going to my condenser and radiator, so instead I and mounted them below the car, behind the left side of the bumper and spoiler. They're just a little forward of the charcoal canister.
SEE PHOTO BELOW.
The brackets are actually mounted to the 240 horizontal support bracket that stabilizes the left fender. It's a TIGHT fit in this space. They just barely fit here, but they all clear and none are rubbing or touching each other or any other car parts. That's important because of how much vibration these things generate.
You might also consider mounting them on the right (passenger) side, since there's more room because there's no charcoal canister over there. This gives you two great locations to choose from. And I think they'll be louder in this lower position with nothing in front of the trumpet openings. It's hard to tell from this photo, but the lowest part of the horns is above the bottom of the spoiler and they're not visible unless you get on the ground a peek under the car.
Photo below view from the ground looking up.
a diagram below I
created to illustrate how I mounted these horns. I
horn brackets to point the horns a bit
forward, moving them away from that charcoal
canister. And then I bolted together each pair of
brackets above the 240 fender brace so that the
brackets sandwiched the brace. I did this because I
felt drilling holes in the brace limited my options
for small adjustments in the final
positioning and my goal was to get these things
positioned just right so none of the horns would be rubbing or touching
or vibrating against
If you're wondering what hole I used to bolt these brackets
together in the above diagram, it's this one
|Send me an email if you do something like this
to YOUR Volvo.
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