Horn relay

[dduelin]

My 1981 R100 came stock with only one horn. I want to add a second horn and have started looking at what relay I would need. I assume I would need a relay but the wiring diagrams show twin horns and a relay on pre 1981 bikes (RS and RT) but two horns and no relay on 81 - 97 bikes. Is the horn switch robust enough on 81-84's to just add the second horn? I'll wire it with 16 gauge wire and the run will be identical to the wiring diagrams.

 

[AnnapolisAirhead]

It should have come with a pair of horns I'm pretty sure (I have an '83 R100). I think the last of the single horned bikes was the /6.

There is a relay bungled up next to the starter relay. You can daisy chain them, but its better to split a wire from the relay to each horn.

 

[dduelin]

It should have come with a pair of horns I'm pretty sure (I have an '83 R100). I think the last of the single horned bikes was the /6.

There is a relay bungled up next to the starter relay. You can daisy chain them, but its better to split a wire from the relay to each horn.

Thanks. The wiring diagrams show one horn for the 1981-84 R100 and earlier /7's. Ian Falloon's Boxer book coorborates. The others I mentioned show two and no relay. I stripped mine to the frame three years ago and didn't remember a horn relay but it could be up in the headlight shell - I don't remember.

 

[boxermaf]

Two of the small stock "button" beep-beep horns will tax the current carrying ability of the horn switch, but it might survive for a while - though will /could burn the contacts in the switch eventually. If you are using the higher amperage FIAMM (snail shell) horns, then you DEFINITELY must use a relay, and use separate wires from the relay to each horn. No sense in installing loud horns, and then having them be strangled by not getting enough juice to fully run them.

If you aren't sure about relays & wiring, Easternbeaver.com has a kit with relay, wires, etc. - everything you need but the horns.

 

[AnnapolisAirhead]

I'll have to take a look at mine, but if you remove the tank, there are two relays on the frame on the left side up towards the front of the bike. On the older bikes, there was just one larger starter relay. The later years have two. One is metal the other is plastic.

IIRC, the plastic one is the horn relay...but its been a while since I messed with that. I'll take a look later this morning. I'll have to get into there anyway, I bought a pair of these: http://tinyurl.com/HellaHorns

Eastern Beaver does have good stuff and worth a look as boxermaf suggests. I get lots of things from them.

 

[lkchris]

Horn switch was changed beginning with 1979 models, and horn relay was eliminated.

 

[Yarddog]

I installed one of those 'Bad Boy' double air horns on mine...available from Harbor Freight Tools, Pep Boys, other places...it's a double air horn and compressor in a small package, and I bolted it onto the battery carrier...it's not in my way, and it's very audible...

 

[AnnapolisAirhead]

I installed a Steibel with their relay. It was loud, VERY loud. Something like 137db. Abotu 120 of those shot back at me when I had the Vetter on the bike...so I went back to snail shaped ones.