Fiamm horn relay wiring

[treoleileagh]

The green book diagram shows the horn relay having three terminals numbered S B and H.
The relay I have has 4 terminals. The terminals are 85, 87, 1 and 1 again.
There is also a yellow wire coming from inside the case that ends with with a female spade connector.

Assuming 1 and 1 are branches of one terminal, which ones correspond to S,B and H? Where does the yellow wire go?
Thanks

 

[Thomas aus LAU]

Which model?

Normaly it works like this:

Sometimes horn plus (30) is (internal) direct connected with relai plus (85). In this case the relai has only three visible cable-connectors.

Thomas aus LAU

 

[Tippie]

I think that on the original relay the yellow wire is a jumper that connects the two + poles, so there is just the one + wire coming from the harness, the other harness wire is to earth via the horn button.

 

[Thomas aus LAU]

Easy to check which wire comes with (+) (when ignition is on) and which wire has (-) when you press the horn button.
You need no instruments only a 12V bulb.

Thomas aus LAU

 

[treoleileagh]

Thanks for these answers.
Chris

 

[Laverda SF]

To be safe, the +85 relay COIL is usually is protected with a 5 or 8 amp fuse and the +30 relay SWITCH protected with say a 15 or 20 amp fuse.

I don't like the 3 cable Relay Switches.

I don't care what horn you're using a Fiamm or a Jap horn they demand a lot of amps to be LOUD and the horn relay has to handle it without failing or shorting out. I usually point my horns at about 25' ahead on asphalt so that the sound reflects !