Horn - upgrading to louder and installing a relay

[jackb]

I’m going to replace my horns; they sound weak and lame. Any suggestions for a good sounding model that fits/bolts right in?

Also, I read elsewhere about wiring in a relay for the horn.... but electical work is not my strongsuit. Has anyone else done this and can help guide me?

[Spittybug]

I went with hi-low air horns from Harbor Freight (https://www.harborfreight.com/automotive-motorcycle/horns/12-volt-super-loud-air-horn-40134.html). I mounted them right on the windshield washer bucket on the lower left front. I used a simple automotive relay and a fused dedicated 12v line back to the battery. The original horn wiring is now simply the energizer for the relay. MUCH louder and effective. Just be careful when working on the car in the garage because you WILL scare the crap out of yourself when you inevitably hit the stem......

[DrJeff]

I rewired my stock horns through a relay (when I was doing my remote door unlock) and onto a different circuit (source and ground lines) and they got much louder. Only reasonable explanation was that the original ground was not a great conductor.

Jeff

[dwaggoner]

I have the hella horn installed on my car. Ryan s has a write up on the forum about it.

[Rich]

.....I read elsewhere about wiring in a relay for the horn.... but electical work is not my strongsuit. Has anyone else done this and can help guide me?

Horns that come with a relay, such as the Harbor Freight knockoffs in that link or the Wolo Bad Boy (also carried by HBF) do come with instructions for connecting them. The HBF item descriptions have tabs that take you to downloadable manuals that explain things for you.

Wiring is straightforward but don't screw up. You should know how to buy the right wires/connectors, safely route the wires, make solid splice and crimp connections and be able to locate both the correct +12V source out of the harness or the fuse box as well as be able to find one of the factory ground points up front. It helps to be handy with at least a 12V test probe light or a volt-ohmmeter. If not then find a friend who is. Your fallback is to make sure the original horns are both working properly.

These aftermarket "loud" horns are very loud. Most of the ones I've seen are air horns. They draw more current than stock horns in most production cars. So much current that a stock horn switch can be damaged if a relay isn't in the circuit so don't be tempted to do a straight swap (without a relay).

[jackb]

I don't need a crap your pants mega-loud horn, just louder than stock. I think it sounds relatively weak compared to a modern, normal horn. That’s all I need. I think my current horn is weak enough to be barely audible by a driver of a modern car, with all the soundproofing they have. My goal is to justvto make my presence known, not be mistaken for a train, haha.

For a relay, I don’t need it direct from the battery? I set up some incredible headlights on my jeep powered directly from the battery and triggered by a relay, it was incredible the difference it made. If I can tap in elsewhere, great.

I understand how to wite up a relay for the trigger; I guess my question is better phrased as: Where is the best place to tap into power for the relay to activate the horn, and where to mount the relay so it is protected without using a whole spool of wire going back and forth from the stock connections->relay->power->new horn?

[Lwanmtr]

Hmm...louder? well..how bout these?

https://www.amazon.com/MPC-Train-Horn-Kit-Triple/dp/B00AA1JD0M

:biggrin:

[Rich_NYS]

Hmm...louder? well..how bout these?

https://www.amazon.com/MPC-Train-Horn-Kit-Triple/dp/B00AA1JD0M

:biggrin:

That's perfect...I'm totally putting these on my car.

[r00b]

I had installed air horns years ago, I really liked the sound. A break fluid leak later fouled up the compressor.

https://www.youtube.com/watch?v=l37fgID-Jc0

[Chris4099]

Are the horns the original factory ones? If so, they are probably just worn out. I went to Autozone and picked up a cheap high/low pair and just swapped out the original ones. Simple and easy to do and will probably provide a nice improvement for most. They won't be super loud, but do the job.

One other note, I knew another owner who's horns didn't work without the engine running. The wiring was just weak enough to not allow enough current through with only 12v, so the horns didn't run. But with the engine running, the voltage increases to 14v which allowed enough power to the horns. So try not to judge the horns without the engine running. You typically wouldn't need them with the car off anyway.

[dn010]

Are the horns the original factory ones? If so, they are probably just worn out. I went to Autozone and picked up a cheap high/low pair and just swapped out the original ones. Simple and easy to do and will probably provide a nice improvement for most. They won't be super loud, but do the job.

One other note, I knew another owner who's horns didn't work without the engine running. The wiring was just weak enough to not allow enough current through with only 12v, so the horns didn't run. But with the engine running, the voltage increases to 14v which allowed enough power to the horns. So try not to judge the horns without the engine running. You typically wouldn't need them with the car off anyway.

I am one of these owners. I bought new horns from Grady to replace my broken in-op original ones. Only the high note works without the engine running. Turn on the car and I get both and they sound good. I am sure wiring is the cause of my issue. Among other things I do plan to do the relay for them when I have time.

[pk2678]

Have a look at this post:

http://dmctalk.org/showthread.php?11865-Horn-Circuit&p=172606&viewfull=1#post172606

This is how I made the original horns louder.

Peter

[DMC-81]

I am one of these owners. I bought new horns from Grady to replace my broken in-op original ones. Only the high note works without the engine running. Turn on the car and I get both and they sound good. I am sure wiring is the cause of my issue. Among other things I do plan to do the relay for them when I have time.

Yes, it is likely in the wiring... a flakey ground or other connection. I bought 2 OEM Mixo horns as well during my restoration and made sure the wiring (especially ground) was solid. They both work without the engine on.

WOW, I was surprised at the loudness of fresh horns. No train horns required. :)

[Mark D]

That's perfect...I'm totally putting these on my car.

Came here for the train horn comment. Was not disappointed.