Can I use a junk car horn?

[FluffyDog6]

Would it be possible to use a regular old car horn out of say a Dodge Caravan (of which I have one available) in place of my anemic Goldwing horn(s)?

How much more juice do you think something like that would draw than a motorcycle horn anyway for brief blasts?

(Seems simple enough, which experience leads me to believe it will require NASA-style engineering to work.)

[Andy Cote]

I would suggest using both of the horns from the Caravan. High and low tones work in synergy to provide a better sound profile.

You should wire it in with using a relay. Not complicated at all. Use the existing horn wire as the "trigger" for the relay and run a dedicated, fused power source from the battery to the new horn(s). Just a small jumper from one of the current horns and leave them in place.

The challenge becomes where to mount them. If you do not have the cornering/fog lights in the lower cowl, there is room there. There is also room up inside the frame by the centerstand. Otherwise, you can go to a visible location outside the fairing.

Check the product review thread on the RIVCO air horn. Expensive but effective. I have also used the inexpensive dual trumpet air horns. I mounted the compressor in the bottom of the right pannier and the horns mounted under the right pannier. There is enough ground clearance. But the horns are subject to all the bad conditions and only last a season or maybe two.

[Snowmoer]

You can also get auto horns without out the trumpet. They will fit where the stock horns are. They are still way louder than the stock horns! I put them on my ST 1300. Here are photos so you get an idea. Agree with Andy, use both of them. I used a relay to supply power to the horns like Andy is talking about.

[Rambozo]

????????

[FluffyDog6]

I'm somewhat confused on how to wire a relay so that too much current doesn't flow through the triggering circuit.

Is there some sort of resistor to keep the flow down?

[Rambozo]

Here is a basic diagram. You can add the relay and optionally keep the stock horns or remove them.
Fuse and wire size will be dictated by the current required by the new horns.

[Limpy45]

I put a set of automotive horns on my 99 GL 1500 a couple of years ago. Wired them like in the picture above and mounted them on the driving light bar that fits under the front of the fairing. Loud enough to get noticed now, don't sound like the cartoon Beep Beep the road runner anymore!