relays and horns

I have 2 stock horns. One stock horn will be removed using it as a trigger for an air horn with an added relay to it and powered from the battery. The other will be left alone for added loudness if any. Will this work? Thanks.

It should.

First most modern vehicle horns are already relay driven, check if yours is (underhood fuse/relay box?) if so you won't need a second relay, just up the horn circuit fuse to 20 amps.and wire both horn terminals directly to your air horn compressor.
Secondly, it's extremely unlikely you'll hear the original horn!

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Yes, there is a horn relay in the car. If I decide to connect to 2 air horn compressors do you think I need to up the fuse to 30 amps?

When you say both horn terminals do you mean just 1 set of a positive and a negative terminals?

I appreciate the help. 1 less step for me.

harryharris wrote:

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First most modern vehicle horns are already relay driven, check if yours is (underhood fuse/relay box?) if so you won't need a second relay, just up the horn circuit fuse to 20 amps.and wire both horn terminals directly to your air horn compressor.
Secondly, it's extremely unlikely you'll hear the original horn!

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Yes to both of your questions, the relay is good for 30 amps constant, if OEM will provide x 2 for short bursts, such as horns.
Except you never originally mentioned 2 compressors, only one.

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That is correct. I thought about 2 horn compressors after you mention the stock horn probably won't add any loudness.

Many thanks, you have solve my question. 1 less relay is 1 less possible problem.

harryharris wrote:

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Yes to both of your questions, the relay is good for 30 amps constant, if OEM will provide x 2 for short bursts, such as horns.
Except you never originally mentioned 2 compressors, only one.

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The db rule, you probably need 4 sets of horns to double the power, the real art is trumpet placement, down and forward with short pipe runs preferably straight, the ideal is the compressor forward of and between the trumpets feeding a short straight pipe run to them.

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Thanks for the db rule. I got excited with your updated info then I realized that under the hood doesn't really have space for 4 sets of horns. I am leaning toward a horn attached to the compressor that seems to be more compact for the available space. The trumpet horn seems a bit too long to work with and I don't really want to deal with the air hose extending under the hood. I love those train horns that I had watched on youtube.