Horns dilemma

[Sergio]

Howdy,
Didn't find anything in a search herein so here goes: I'm looking to install 2 Hella 400/500hz horns. Has anyone done this? At 2x72W do I need to add a Bosch relay, or can I just plug & play using the existing single horn wiring? (That would be great!) As I'm colourblind I'd appreciate some help before the smoke test. I do have the manual and the full-colour wiring diagram jpg (thanks for that post) These LOUD horns are an absolute necessity amongst the antique drivers around here. I had them on my GPZ550 long, long ago.
Thanks

[The Cheese]

You'll need to add in a relay to handle the load. Use the stock horn wires for the relay ground and trigger. Then just battery in and out for the other two relay wires. Lots of good pics on Google to show which wire is what in the relay. You'll have to measure the stock wires to determine which is ground.

I think Eastern Beaver sells the horn relay kit. If you don't want to make your own.

[ParcNHawk]

I would use a relay.

It's really easy to test them on the stock wiring though.

I agree with the need for loud horns. I use a Stiebel Nautilus air horn and the compressor is relay-activated.

Use a fuse to protect your relay's power lead.

Colorblindess won't hinder some of this, as both horn wires are black. Use a VOM to determine the polarity.

[Sergio]

Thanks, all
Like this pic? (Which I hope shows up)

[ParcNHawk]

That would do it.