I installed a plastic coated wire harness in my late '47 1/2 ton. My question is because of where the stock horn mounts on the intake, the wire harness exits the wires near that area. On my truck I have a dual horn mounted to the firewall on the passenger side. Did the horn originally mount on the firewall or is this possibly an aftermarket add on?

The Horn belongs on the intake...the horns on the firewall were just added there by someone who thought that would be a nice spot for horns....Kevin

The correct location for the standard horn is on the intake.

The correct location for the ad on GM accessory dual horn kit for the trucks (GM part # 986397} is on the passenger side of the firewall.

Rather than being a random spot to mount the extra horns.... the installation instructions are actually very specific about where they are to be mounted on the passenger side of the firewall.

Wow , Thanks M.T. For excellent post w/diagram . I don't recall seeing that horn set-up before...I take that back...I've seen them on a Panel Truck here in town...

Thanks M.T. My horns are mounted side by side rather than top and bottom as the diagram shows. I guess instructions serve the same purpose then as they do now. Packing material.

Steve , maybe the previous owner came by the horns sans instructions...is there a relay in your circuit ?

Yes there is a relay.