Using 1" x 1" aluminum angle, I created a holder for the air compressor and horn assembly. After being painted black, mounting the compressor and horn to it, I mounted the whole assembly behind the grill onto the A/C condenser's top bracket.

A few closeups of the bracket:

And for those interested, here's the circuit design to control the air horn using a dash button, enabling either horn to operate normally using the steering wheel:

Drawing was edited for clarity and corrected on 1/4/21.

The Low Voltage Relay, in a small hobby box, is located under the dash near the installed horn button, drawing power from the fuse box using a fuse tap. 30 AMP relay will be located under the hood behind the driver's side OEM horn and drawing power from the engine fuse box using a fuse tap.

Have a good day.

 

Gorgeous work!

 

Thanks. I'll post when completed with a video featuring the sound difference. The air horn openings are pointing directly at the lower grill openings. Sound should get thru pretty loud.

Have a good day.

 

Some more photos of the air horn install.

Tapping into the horn wire on the steering column. I cut the horn wire and redirected the wiring down into the Horn Relay Box. You can see the two wires (Yellow & Blue) coming out at the brake pedal. The HRB is visible bottom center, with the long white wire that had to be passed thru the firewall to the high amp relay. I was able to use the hood release cable path by removing the front driver's wheel liner for access, so nice and clean install.

The horn button installed, along with a new LED switch. They both are the same amber as the other OEM switches. When pressed. each has an indicator LED lit showing the circuit is active.

For those interested, it seems that the power steering wheel adjusters motors have been upgraded to brass from plastic for the gears. You can see it in the center of the photo.

While removing the front driver's wheel liner to install the air horn trigger wire, I discovered that my ground lighting has taken quite a beating over the last three years since they were installed in Feb 2018. Checking the other three wheel wells, all the LEDs were all pretty well shot. I'll be adding photos and updates to the LEDs to this post:

2017.5 Munaro Platinum Upgrades! | Page 9 | Nissan Murano Forum

I'll be posting a video of how the air horn sounds in several days.

Thanks for looking.

Have a good day.