TOPIC:

A cop bike having an OEM horn that squeeks instead of blares was no surprise to me since what self repecting cop would use the OEM horn when there was a siren a fingertip away. So I have replaced it with one that blares (when connected directly to the battery), but alas still a squeak when connected to the original horn wires. Problem 9.98 volts at those horn wires. Why is this. And what solutions. I just want to be heard.

John

check horn button,contacts dirty?

Sounds like it's not grounding thoroughly to me.

I'm not sure if the same applies to your bike or not, but on my 650 the handlebar switch housings ground to the handlebar itself. I found this out after I changed the handlebars and my horn didn't work at all.
I just ran a wire from the ground connection on the horn switch to a known-ground wire in the harness = "beep! beep!"

You may need a relay for the horn. If it draws more current than the switch or wiring is set up to handle, it will wreck your switch. Wired George coil mod will work for the horn too. Power relay coil through the horn button and switch juice from battery with the relay. I recommend connecting through a fuse.

Just picked up a two tone air horn here. Got it at the thrift store for $cheap including the compressor. Just have to figure out how to mount it.

-Duck

I have used relays before. In fact on this bike, I replaced the blue and the red lights up front with Harley spots and wired them through a relay. However will a relay trip on less than 12V.

Most 12V relays will pull in with around 6-8V. If you measured voltage with horn attached, you'll likely get a higher reading with lower current drawn by the relay coil.

-Duck

If the horn is pulling less than 10VDC, the contacts at the switch are dirty and should be cleaned. Also, before trying a relay, check on your horn for a slotted screw. This screw may provide tone adjustment. Most horns have an adjustment because as they age, the tone will go from BEEP to frltttt... All the horns on all the bikes I own have this sort of screw pot adjuster.

Just had same issue with my 95 GPZ1100. Horn switch in handlebar control was dirty. Dissassemble, clean and good to go. Lotsa small parts and maybe a tiny spring so keep an eye open.