I got the Howard's Horns this week and finally got around to installing them last night.. I had to drill out the hole on the cowbell hanger because the bolts that came with the horn were too big. Then, I had to rummage through my parts bin to find a 5/16 nut because they shorted me one. And now I can't figure out how to run the wiring. They give you a rough schematic and some vague instructions for wiring, and then recommend you have the wiring done by a "certified mechanic". Sounds like liability wiggle to me. So, bottom line, my question is......Can anyone please walk me through the wiring of the relay for the horn on an Ultra Classic?

 

Schematic...........http://howardshorns.com/relayinst.pdf

 

That looks prety straightforward to me. Get your voltmeter and find the wire at your existing horn that has +12volts when you press your horn button. Run that wire to horn relay terminal 86. (86 & 85 are the relay coil terminals) Wire terminal 85 and the negative terminal on the compressor to battery negative (-BAT)
Find your main Bat+ connection and wire it to relay terminal 30. Last, wire the + terminal on the compressor to relay terminal 87.
When you press the horn button, that will energize the coil of the relay. This will close the contacts between terminal 30 & 87, and power up the compressor, activating the horn.
Oh, also, like the instructions say, make sure you use at least 14 gage stranded wire for these connections at terminal 30 & 87. Those connections will be carrying the most current.

 

They're also saying to use 14ga "automotive" wire. Is there a difference? Thanks for the help Doc
Frank

 

14ga is 14ga, the only diff between automotive and standard may be the insulation (oil resistant).

 

No problem, no oil on the outside of a Harley
Thanks

 

OK, I drank a beer, took a deep breath and cleared my head, looked at the schematic again, and..........................
the light came on. That's easy!
So I wired it up temporary to test it. Pushed the button and WOW, sounded like a freight train. So I unhooked everything and started the permanent wiring. Snaking and hiding it. Great, done, push the button, NADA, NOTHING, no noise. Check the fuse. Fuse is blown. Swap out fuse. Push button, it blows again. Put the volt meter on the negative post of the battery and the relay tab where the horn button is attached. It reads 75 volts.???????????WTF Is it a bad relay? I wired it exactly like it was when it worked. Now I'm perplexed. Any idea's? Can it be a bad relay?

 

I can't even imagine where you would get 75volts! Only way you could get anything close to that is from the AC Voltage output to the regulator.
You better go back thru and recheck your wiring and connections.

 

I checked everything four times. I may have read the multimeter wrong. I do know it's not wired to the wall outlet. I'll check three more times, but that's it.

 

OK, when I got home last night I thought about each connection and whether I had any doubts. I felt good about all but one. The splice to the existing horn button wire. I put heat shrink tubing on the splice when I did it. I cut that section out and made a new splice. Hooked it to the relay, and...........................................







WHAAAAAAAAAAAAAAAAAAAAAAAAA!!!!!!!!!!!!!!!!!!!!!!! !!!!!!


It works! I think I put too much heat to the splice and melted the insulation on the wires and caused the pos. & neg. wires on the horn button to make contact and short out. Thanks for the help guys!