Post below is from a couple posts I did on the "V-650 > What did you do on your versys today?" thread.
Installed onto a 2017 Versys 650 ABS
I finally got around to installing my Stebel Nautilus Compact Mini Air Horn (11690019)
Longest part was trying to figure out where to mount it. I wanted to mount it where water splashing from the front wheel wouldn't directly enter the horn openings. I thought it could fit in the front headlight cowling (Gen 3), but the horn is too big. I have a California bike, so the left wing is occupied with the charcoal canister.
I finally decided on mounting it to one of the T-Rex engine guard mount brackets (not onto the engine guards themselves) on the left side, lower half of the engine guards. It's tucked away and safe from harm.
I also got some timer delay relay circuit boards, this is so I can control two horns with the single horn button. So, I can use the stock horn for the first half second to meep meep someone, before the loud air horn kicks in a half second to a second later if you hold down the horn button. But, it got too dark in the driveway. So, I just disconnected the factory horn and tapped into the end of the OEM horn wiring connectors for the air horn relay. I'll work in the timer delay board another weekend.
Not quite finished the air horn install. I have some split loom on order from AMZ to hide the 14 ga. colored wiring. The air horn relay is under the left wing.
Drilled a 3/8" hole into one of the steel brackets supporting the T-Rex engine guard. Used the supplied mounting bolt to mount the air horn to the bracket. Should be out of the splash area of the front wheel.
If you're wondering what that black 90-degree connector is, it's the remote air intake for the horn. Going to put a hose and route it to under the seat for clean air, to prevent it ingesting dust from off-roading.
Tucked in and out of the way. Worked really well on the commute this morning.
Got the attention of distracted cagers.
I tidy'd up my air horn install, I covered up the air horn wiring with some split loom and zip ties.
I wasn't sure if I was still going to use the OEM horn with a delay circuit relay. I haven't cut or changed out the connectors yet, I just used some heat shrink tubing to make it more weather resistant.
Air horn relay install location, near the California bike charcoal canister. Mounted onto the canister metal bracket and using one of the existing factory bolts to mount the red relay.
This pic shows where I drilled into the T-Rex engine guard support bracket to mount the air horn with the supplied bolt and nut.