2010- Button Horn, Aftermarket Replacement

I just bought a $1000 white beat-up 2010 Prius with 298,000 miles. A lot of work to be done to get back on the road. Fortunately for me and after ~3 months, I got all minimum maintenance tasks done less the horn, a necessity for passing the vehicle inspection. The former owner claimed he had a vehicle spin out on ice that damaged the front end of Prius.

MATERIALS
- $10 horn, high tone
- $7 8 gauge wires and horn button
- 8 gauge speaker wires; i used this over the wire that came with the hor button package

ASSESSMENT
- STEERING WHEEL HORN- didn't work
- FUSE- was missing; replaced with a new 10amp fuse but still didn't work
- RELAY- the original horn relay was not there; replaced it with a new one-- the horn still didn't work. Swapped places with another relay next to it-- the horn still didn't work. A friend helping me, told me the relays didn't make any clicking sounds.
- FRONT HORNS- didn't bother as they are buried under my front bumper that is put together with +12 zip ties and washer.
- DECIDE- EASY/CHEAP BUTTON- My techstream readings didn't show a historical steering wheel airbag deployment, but my intuition tells me something in that steering column is broken and limiting the horn's performance. Airbag clock springs alone cost ~$45-$200, ranging from used to new. I ultimately decided to not open up the steering column to replace the horn, and to commit to an after-market horn.

UNPLUG THE 12V REAR BATTERY.

FISHING WIRE.
- I found a through port in the firewall just under the steerign column
- pushed a coat wire through from inside the firewall to into the engine bay. I then hook-pulled the wire (sprayed it with silicon spray first) back in cabin from the engine bay.

HORN BUTTON.
- I decided to place it high left of my knee on the dashboard
- removed a small dashboard panel near my left knee
- i hooked up the positive & negative cable to the horn button
- i knotted the wire to ensure it didn't recede back into and behind the dash panel

HORN ENGINE PLACEMENT.
- I placed the new horn in front of the positive battery terminal within the engine fuse box
- connected 1st wire line to the positive terminal
- connected 2nd wire directly to the horn
- from the horn I grounded a 3rd wire to the engine frame

OPERATIONAL TEST.
- reconnected the 12v rear battery
- silly, I actually went for the steering horn... dud, then reached down and pushed the new horn button
- honk, honk--- nice.
- now, I'm finally ready for the state inspection