Aftermarket horn wiring

I have a 1986 Maxim 700 and bought a pair of aftermarket horns. The horns are supposed to be louder and come with a relay. I tried unsuccessfully wiring the horns. Can anyone try to put this in simple steps for me?

Thanks

 

Easy:
1 - run wire from relay ground terminal to ground point.
2 - run power line from the battery or fuse box goes to the provided relay.
3 - the original signal wire from the horn becomes the switch wire on the relay.
4 - run wire from relay switched output to your new horn.
5 - ground the horn as well (if needed).

Done - that should do it.

 

Exactly what Altus said.

Some silly background. The horn on many bikes is ground switched - meaning it always has full power to the horn, but it is isolated from ground. Pressing the horn button connects it to a ground source.

This wiring is often light gauge, so if you were simply to use this wire as the power source you'd be current limited.

Some people like to keep their OEM horn as well, and they try to wire the horn in series with the switched side of the relay. This will not work because the relay switch is only designed for a small trickle of power.

To make optimal use of the OEM horn as well, do as Altus said - wire the horns from the switched power from the relay.

For diagrams on this I'd point you at the ninja 250 FAQ...

http://faq.ninja250.org/wiki/I_want_a_louder_horn

 

Thanks all, I'll give it another try, sounds like what I tried but must have missed something.

 

Well, as Woot said, many bikes are ground switched for the horn. I don't know whether yours is, but the older XJ's certainly are. If your stock horn is ground switched, then the procedure would be more like this:

1. 12V from battery, through a fuse (10A or so), to relay pin 85 (assuming basic 12V Bosch-style SPST relay), and to horn +

2. Relay pin 87 to ground

3. Relay pin 30 to the horn -

4. Relay pin 86 to the horn switch ( - side of original horn)

Hope this helps.

Paul

 

Ok i got curious and tried this myself. it's too cold to ride here anyway. I own a 82 SECA 750.

I went to Advanced Auto and got a FIAMM Highway Blaster low tone and a regular 12V relay. Got home and unbolted and dissconnected the stock horns. I hooked up the relay like this:

87- inline fuse to positive battery terminal

30- new horn positive

85- old horn wire positive

86 - old horn wire negitive

Don't forget to run a wire from the negitive new horn post to the battery.

That's it. Fabricate a bracket and screw it down. New one is much louder. Check out this video. Notice the echo from the new horn.

*New Horn*

 

Yup, that's another alternative. Joe's version switches 12V, mine switches ground, but the end result is the same.

The only other difference is that Joe's circuit depends on 2 12V fuses - the new one added in line with pin 85, which will supply 12V to the new horn, and the Signal fuse in the fuse box that supplied 12V to the original horn. Not really an issue, just something to be aware of as an extra thing to check if/when troubleshooting a non-working horn.

On the other hand, regardless of whether your bike's original horn is ground-switched or 12V-switched, the wiring for Joe's circuit would work without any changes.