Topic: help with horn relay

[jvalbuena]

I'm trying to install dual, high output horns on my '77 CB750F. I did a seach on this site and found a link to http://www.rattlebars.com/mtz/hornrelay.html.

It's a very good site. I'm using a relay as suggested to keep from frying the horn switch. My problem is that the horn switch (LG on the wiring diagram) on my CB grounds the oem horn to make it work. It is not a "hot" wire so it can't trigger the relay to make it work. So how do I wire the relay?

[TwoTired]

If you are using the relay pictured at that site.  Wire pin 85 to the LG wire and pin 86 to the Black wires that went to your old horn.
This assumes that relay doesn't share any common grounds.  As it doesn't give any relay internal wiring diagrams, I can't tell for certain.

Cheers,