Installing 12 volt air horn

[fourfourto]

I need a 12 volt wire to tap into under the hood or is it better to tap into fuse box. I also need to run wire from under hood to switch on dash.In another thread i was told that the lower black grill pops out with clips i didnt want to force it is there a easy way to do it. Any info would be helpfull.

H3 gray aventure ,sunroof, steps ,roof rack ,smokers package ,window vents, sunroof visor, hard spare tire cover, h3 valve caps ,mudflaps and K&N filter 2,900+ miles

[4ophenia]

fourfourto, what make/model did you end up getting? I'm assuming you're trying to fit this under the hood, or perhaps directly behind the grille.

I've been looking for an air horn with a deep, strong sound and would like to know how you like the horn and how you installed.

Thanks

[fourfourto]

I havent installed it yet .Its a inexpensive horn from harbor frieght 135db. going to mount horn behind grill the compresor/relay behind left headlight under hood. im not sure were to tap in for 12 volt source also have to run switch wire through firewall. The lower grill needs to come out to get the 2 horns in there someone said its cliped in.I want to make sure i dont damage it .Hopefully ill get to it this sunsay if it dont rain. I found a switch that will install in dash spot at radio shack.


H3 gray aventure ,sunroof, steps ,roof rack ,smokers package ,window vents, sunroof visor, hard spare tire cover, h3 valve caps ,mudflaps and K&N filter 2,900+ miles

[Klint]

FourFourto Man I hope you have taken your H3 apart because it is HARD TO GET TO GET TO THE HORN! Also Don't run it through your firewall run it up the bottom of the H3 and then up to the Door Pan. the plastic plate comes off drill a hole and run it itn there that way I think there is a guy that did it htat way

[fourfourto]

I would prefer to run it through the firewall.Only 1 negitive wire is needed for switch.Seams like theres a few spots wires go into firewall. if i cant figure it out its good to have other options. Does the lower grill come out easily ?.

[f5fstop]

What's the max amp draw of the compressor? Being an electrical guy, and knowing how tempermental computers are, I always recommend installing any additional power source that draws 10 amps to run through a relay.
That way you can tap into almost any hot wire under the dash (other than computers signal circuits), run this wire to one end of the switch, from the other end run the wire out of the dash.
Hook this wire to the switch side of the relay, find a ground, and on the coil side, tap into a direct B+ wire. From the other side of the coil connect to the compressor. In addition, it is very important that the B+ wire is fused as close as possible to the source of the power to prevent any wiring damage, and fires.

[4ophenia]

H2 horn would be louder and perhaps easy to install in the H3.

[4ophenia]

So, fourfourto, how'd it go with the new horn? Did you install yet? I'm thinking of going with the H2 horn myself, but am curious about your install.

Thanks

[fourfourto]

I didnt get a chance to install it yet(wife uses truck to work she gets home its dark)Ive been busy. I did try to pop out lower grill didnt want to go.(someone said it pops out with clips ?.) I dont want to break it ill try again on sunday if weathers good.I was going to tap in to battery but didnt want to disingage power figured it would cause problems.I will list pics when i install have know way of sending sound file.

[H3Eric]

Hi, I actually installed the PIAA horns. We expected a deeper sound than it actually is. There is some work to get to the horn but it should not take more than 10 minues. You can take the grill off by removing some bolts between the 7 bars and on top of the grill under the hood and the rest around the headlights is with clips. (it is some months ago and I don't have the car here at this moment otherwise I would check)

I was thinking about installing an airhorn as well and use a swith inside to switch between the regular (PIAA) horn and the airhorn.

Eric
Black H3 adventure

[fourfourto]

H3eric I need to tap in for 12 volt any ideas other than the battery? Im going to mess with it on sunday.

[H3Eric]

Fourfourto, I don't have an answer to another 12 volt location. The PIAA horns can be connected to the existing wires with new connectors. These wires are very thin, not strong enough for your airhorn.

I will look under the hood if I find a good place I will let you know.

[x-humm]

Anyone knows where I can get 12(+) volts supply from the engine compartment beside the battery. If not what is the best way to hook it up from the battery terminal.

[fourfourto]

I scoped it out on sunday i ran the neg wire from relay(im going to mount it under hood) to dash installed momentary switch from radio shack. I went through cable on drivers side hooked ground up to existing wire cluster(i beleve there for trailer brake)Im going to tap in at battery for positive and main ground. If to lift battery covers at terminals theres a nut and threaded stud you can put a eye loop connector on there very easy just make sure you have fuse as close to tap in as posible.I havent put in horns yet I have to remove grill or lower grill ill get to it this sunday for sure.I have to pick up 2 eye loops and a mounting bracket.

[x-humm]

Hey Fourfourto,

I tried putting an eye loop connector in battery terminal but the way the nut adjusts to the battery terminal, it won't work.

I tried finding a nut that matches the same thread of the battery terminal but no luck. I think it is metric. So I can use it to install the eye loop connector.

[fourfourto]

I assume you are going to double nut it thats what I probobly will do I guess I have to p/u 2 nuts before sunday . Is the original nut tappered you cant tighten down on eye loop to form a cone ?? or maybee a u connector ??

[fourfourto]

I looked at it this morning I see what hummer nut means if you loosen nut on battery it backs off tension on clamp It almost feels like nut dont want to back off(tight on threads)Theres no way of puting eye loop under nut.I did match nut(had them left over from motorcycle battery 10mm)solution put eye loop over nut then add extra nut .It should work fine for tap in and doesnt effect top cover of terminal.I tested horn with extra battery in garage and seems very loud 135 db cant wait till sunday to finish install.


QUESTION... does that lower grill just pop out with clips(someone here said it does) I tryed to remove and didnt want to force it.The smaller horn fits in between slots on grill bigger horn almost fits through a little force it might squeeze through but I dont want to chance cracking grill or horn ?(there is a little flex on grill) Any info would be helpfull.

[H3Eric]

Fourfourto,

There are 4 bolts and clips on the chrome large grill. Two bolts near the most left and right vertical slot. and 2 bolts under the hood in font of the radiator. Then there are plastic clips around the headlights on both sides.

[fourfourto]

H3eric Ill try that this sunday I was hoping lower grill would snap out easy.For a easy project it seams like its taking me forever to put these horns in ill finish sunday no matter what.Then ill drive around blastin horn at every ******* I run into.

[HUMTECH]

Remove cover from UBEC (underhood bus electrical center) front left of engine compartment and you will find 2 studs that will supply 12v. there is no interior fuse panel on an H-3. Be sure to fuse power supply after UBEC so not if but when horn screws up it will be a cheap fix.