I wasn't sure where to park this thread, so I figure it's not quite interior, not quite exterior.... But it is audio lol!

I've been meaning to post about this mod, it was completed shortly before the GM Nationals, but I was not totally happy with it at the time and found out why after I got back (one of the 4 horns bench tested good, but on the car was bad, I had to replace it).

And, well, with Keanne and the air horn, there is still no comparison who wins (I'm jealous Keanne, but I'm over it lol, I don't want to put an air pump/compressor in my Monte, but sweet set up).

Anycase, here's the scoop on my horn mod.

Reason I did this: My wife's Impala had a dead horn and it uses the same dinky horn setup my Monte used. I decided her car could get my Monte horns and I can upgrade to 4 note Cadillac horns (slightly louder and a more unique tone).

Now the mod: The horns have 4 notes, each labeled (A, C, D and F). There are two different styles of these. The single wire with a spade connector (they ground to the body of the car where you bolt them up) and a 2 wire connector style. I'm using a 2 wire connector setup.
There is some debate over which ones are louder. I've compared both sets with a decibel meter, they are the same. I've compared them against the factory horns in the Monte with a decibel meter and the Caddy horns only rank about 5 decibels higher. Some may find different results. All the Caddy horns I tested were early 90's. I've heard that maybe the mid-80's Devilles may yield louder results (and I'm waiting to find a set in the junk yard, I'm curious).
Admittedly, I did expect them to be louder then they are, but they are still cool. The tone does remind me more of a "train" horn sound (so not as loud as a true air driven train horn).

Moving forward.

My dad and I wired these up so NONE of the Monte factory wires were ever cut! Also, no additional holes were drilled in the body!

- The factory horn wire now plugs into a male connector (that used to be for a ABS wheel speed sensor), that is now a trigger for a relay.
- I have a wire that connects with the battery wire to the fuse panel under the hood, that wire goes to a 20amp fuse and supplies power to the relay.
- We made special brackets from a piece of stainless steel. Two of the horns are in the factory horn location, and GM was nice enough to leave the same mounting holes on the opposite (driver) side, I just had to run a tap in the one. So, no new holes in the body!
- The two passenger side horns and the relay ground together (hooked the ground to a bolt around the hood latch).
- The two driver side horns ground to an existing body ground.

All wiring is soldered and covered in heat shrink tubing. Some of it required new wiring loom and others run in a factory loom. If I ever wanted to remove this setup, it's pretty much plug and play

So when I hit my horn, the original horn wire trips the relay that now supplies power direct from the battery, through the relay, to all four horns. I don't think it gets any cleaner then that.

And now, some pics of this setup.


Factory Monte/Impala 2-note horns (probably the same in most modern GM cars). These happen to be the Impala ones (my Monte ones were a little cleaner but not by much). The bracket is the cheapest/flimsy thing. The mater part of the horn housing is just covered in rust.


4 note Cadillac horns


Caddy horn compared to a factory horn (a little size difference).


Tough to see, but in the next two pics, there is a wire connected to the bottom post of the fuse panel and goes to a wire. You may also notice to the left, the red fuse holder (hides nicely in the fender space, but I pulled it out a little for the pics).

 

The wire from the fuse case in my hand.


Here is where the factory horn connector now connects to a harness for the relay and Cadillac horns. The harness was all built in place (not on a bench).


Passenger side horns (mounted in the spot the factory horns sit in). FYI - There are star lock washers in this assembly that prevent the horns from swinging and from the bolt backing out. Using a bolt that went all the way through made this assembly very solid!




Wiring harness continues. The wires in the new wire loom are for the relay. The wire supplying power to the other two horns is hidden in that factory wire loom to go over to the other horns.

 

You will see the relay, it's taped up to the factory harness. You will also see the ground for two of the horns and the relay on the bracket for the hood latch.


The other two horns on the driver side (a lot more room on this side).


The wiring in my hand is the ground wire for those two horns (it is actually the complete factory original ground wire from a donor car at the junk yard, so the ground is uncut/unspliced for that side). It shares a ground with a factory ground point.


An identical bracket setup like what we used on the passenger side.


Below is the simple wiring diagram this set up is modeled after for those interested.
Except where they show a horn, for me that is two horns per one horn in the diagram.

 

So what does everyone think? Wiring wise, I think it could pass as a factory set up. And the brackets didn't turn out too bad.

 

`Jason,


Super Write `up on your new Mod 4>Sure
We need a sound clip (?)
Thanks for posting/Sharing

 

Ask and ye shall receive. Attached are clips from outside and inside the Monte with the new horns.

 

LOL, you just love to be in someones face don't you.... Look out coming through HONK HONK HONK.

Seriously though the horn mod is probably one of the most underated mods, yet can be one of the most attention getting ones. Like the way you reused the Monte's horns in your wifes car instead of condeming them to the junk pile.

Great write up for this whole procedure, your always so thorough with your work. Nice you did not have to puncture the Monte with additional holes, just tap out an existing ojne. Good info to know, I might have to look into some horns too, as the 2 note ones are just pretty well blahse and probably don't get so much attention when you need them to.

LOL, Keane's were crazy, Devin would provoke him to blast them at the Nat's when the Florida Monte guys cranked their stereo too high, they got everyones attention.

Hey 5 db is 5 db, your so thorough with your work, you even metered out the DB differences. And the quality of the wiring in process is second to none, nice you configured the new wires to be a plug and play. Great pictures to accompany the write up. You rock!!

 

Thanks Admin `Jason for your reply & sound links. You sure are a man that pays attention to details....

I wish Santa Claus would follow your example > "Ask & ye shall receive" > I keep asking him, but still don't receive what I ask for (I guess one has 2 `be GOOD 2 receive) > LOL