Wiring in an aftermarket horn

[BigWaylon]

First…I’ll start with the pic from the Amazon ad:



And then the instructions off the box:




None of that makes any sense.

Here’s what’s in the box, and the horn:





Can’t I just ignore all that and wire it using a standard 4-pin relay diagram, like this:



I want to leave the original horn in place. So I need to tap into that wire to go to pin 86. Run a fused wired from the fuse box to 30. Take 85 to ground, and the – pole from the horn to ground. Then 87 to the + pole on the horn.

Just have to ignore all the connectors on the wire they supplied, as none of it fits anything useful.

 

[Jeppo]

Ah-ooga horns went out of fashion in the 70s. Didn’t you get the memo? 😂

 

[Shady Grady]

 

[SPST]

I've got one of those on my motorcycle. I have it wired and fused directly to the battery. Mine is triggered from the original horn wires to the relay. I'm not sure how to wire it for both horns though

 

[heavydoc]

iirc, the horn has a constant power and the ground is what is switched to activate it.

 

[noway2]

Yes, use a relay. The diagrams they’re showing look like they keep the +12v as common and switch the ground using a relay, or possibly (my guess) transistor as it’s pretty easy to use one as a switch to ground.

 

[Get Off My Lawn]

That's the worstest ChiCom wiring diagram I've ever seen.
I have a similar horn & wired it like so. Output + of relay to horn, horn and relay negatives to chassis, relay input connected to original horn input.

 

[BigWaylon]

Yes, ignore their ”information” and wire it to a relay and be done.

Maybe this guy’s diagram helps.

View attachment 567547


Also, Google Wolo horn install. Should be similar.

I had that pic saved already…but the jumper from 30 to 85 didn’t make sense to me. Plus, there aren’t two + and two - connections on the horn itself.

Might give it a shot this weekend. It’s going on my son’s car, so I’m gonna wait until he’s here to help (or at least watch). 😁

 

[Red Marley]

Does it play Dixie?

 

[Scsmith42]

I had that pic saved already…but the jumper from 30 to 85 didn’t make sense to me.

Think of it this way. The relay needs a hot wire for the circuit to activate it (switched side), and a second hot wire for the circuit going to the horn itself (load side). Typically the switched hot wire would be a low current, small gauge wire, and the load circuit (actual horn) wire would be a higher current, larger gauge wire. So in many applications you might have an 18 gauge, 3A fused wire for the switch circuit, and a 12 gauge, 30 a fused wire for the load.

30 an 85 terminals are the two "power in" terminals for the relay. One of them goes to the coil (and is completed by the grounding through the horn button), and the other to the load (horn). By jumping in-between them you're sharing one power cable to the relay instead of two.

The drawback to jumping them is that you lose the lower amperage fused wire for the horn activation circuit (which can keep you from melting a wire if the circuit ever shorted out). The benefit is only needing to run one power circuit to the relay.

Clear as mud? (grin)

 

[BigWaylon]

Think of it this way. The relay needs a hot wire for the circuit to activate it (switched side), and a second hot wire for the circuit going to the horn itself (load side). Typically the switched hot wire would be a low current, small gauge wire, and the load circuit (actual horn) wire would be a higher current, larger gauge wire. So in many applications you might have an 18 gauge, 3A fused wire for the switch circuit, and a 12 gauge, 30 a fused wire for the load.

30 an 85 terminals are the two "power in" terminals for the relay. One of them goes to the coil (and is completed by the grounding through the horn button), and the other to the load (horn). By jumping in-between them you're sharing one power cable to the relay instead of two.

The drawback to jumping them is that you lose the lower amperage fused wire for the horn activation circuit (which can keep you from melting a wire if the circuit ever shorted out). The benefit is only needing to run one power circuit to the relay.

Clear as mud? (grin)

30 is (fused) power in, and 85 is the relay ground. Right? That’s why it makes no sense to me to tie them together.

86 is the other power in (trigger/signal) from the existing horn wiring.

 

[Fordtruckfan89]

Terminal 30 can be ground or power, the relay doesn't care. When the relay isn't triggered, 30 is connected to 87A. When it's triggered 30 is connected to 87. On most relays you don't have to have 85 as ground and 86 as power, they can be reversed and still work. Some relays are polarity specific. Hopefully this helps

 

[Scsmith42]

30 is (fused) power in, and 85 is the relay ground. Right? That’s why it makes no sense to me to tie them together.

86 is the other power in (trigger/signal) from the existing horn wiring.

Ah, now I know why you're missing this.

85 and 86 are the two ends of the magnetic coil portion of the relay. It doesn't matter which terminal is positive and which is grounded, but when that circuit is energized by grounding the horn button it engages the contactor. When the contactor is engaged by the magnetic coil, it completes the circuit between 30 to 87.

So by tying 30 and 85 together, you're providing power to one side of the coil and one side of the contactor. Alternatively, you could tie 30 and 86 together if you prefer, and use 85 for the horn button. It doesn't really matter since the circuits inside the relay are all isolated.

 

[BigWaylon]

Put two wires on the horn and touched them to the battery…just to see.

Definitely louder than the factory horn on his Sentra. 😁

 

[Scsmith42]

^^^ Yes you could.

 

[turkeydance]

back in the day, i installed a more powerful horn in my station wagon.
it worked well, except for the 1/2 second activation delay.
old tech, so i am sure it is much better today.

 

[ronn47]

Put two wires on the horn and touched them to the battery…just to see.

Definitely louder than the factory horn on his Sentra. 😁

So a louder horn is what you are wanting?
Get a 6 volt horn from a '50s era pickup.

I had a '53 Ford F-100 that I converted to 12V and keep the 6V horn.
People JUMP when I would beep it.

 

[BigWaylon]

So a louder horn is what you are wanting?
Get a 6 volt horn from a '50s era pickup.

I had a '53 Ford F-100 that I converted to 12V and keep the 6V horn.
People JUMP when I would beep it.

It’s just a little wimpy. This one will be plenty loud enough. I paid ~$22 or so for it.

The kid was shopping around for one that was $600…and has ~$50 to his name. 🙄

 

[NCMedic]

I still want to put these into my Tacoma
Four Delco-Remy horns from a 1985 Cadillac DeVille. Each horn plays one unique note, in this case A - C - D - F respectively.



I've also been told there is enough room in the grill of a 3rd Gen Tacoma to support 2 sets... 8 horns.

 

[ronn47]

I still want to put these into my Tacoma
Four Delco-Remy horns from a 1985 Cadillac DeVille. Each horn plays one unique note, in this case A - C - D - F respectively.



I've also been told there is enough room in the grill of a 3rd Gen Tacoma to support 2 sets... 8 horns.

Ohhh
Those are cheap to buy too

1985 CADILLAC DEVILLE 4.1L 250cid V8 Horn | RockAuto

RockAuto ships auto parts and body parts from over 300 manufacturers to customers' doors worldwide, all at warehouse prices. Easy to use parts catalog.

www.rockauto.com

 

[Fordtruckfan89]

I usually just use fiamm freeway blasters. Simple to wire in but a little louder.

 

[GoWolfpack]

Used to be a guy around Raleigh who took about 40 horns from junkyard cars and wired them all in line with the factory horn on his van then tied them all over the grill. Told me he had so many it bogged down his alternator and he needed to add a second battery to power them all.

Weird guy.

 

[Catfish]

My Harley has the factory horn, a Cadillac horn, and a set of air horns. It's still not enough to make CLT roads safe, but it sure is fun to startle Karen at the wheel when she's paying more attention to her phone than the road.

 

[Scsmith42]

Y’all need a horn like this one…

 

[noway2]

My Harley has the factory horn, a Cadillac horn, and a set of air horns. It's still not enough to make CLT roads safe, but it sure is fun to startle Karen at the wheel when she's paying more attention to her phone than the road.

I remember there was another thread on real car horns and someone mentioned installing one that was so loud it would make the idiot ahead of them spill their coffee.

 

[BigWaylon]

Got it installed today. Only issues were self-inflicted. Noticeable difference.