How to wire in an extra car horn with a switch on the dash?

Hello! I have an extra car horn and I need to install it into my car alongside my other horn, and I have no idea how to wire it! Here is what I have: a Car horn with two wires (black and red, and red) 16G wire, a switch, and a inline fuse. I need to know how to wire it to the battery, and how to ground it. Does anyone have any experience with this? Any help would be greatly appreciated. 

noahwinter357 (author) 4 years ago

Is the car the ground? So just run the black wire to the car, then some were were the line attaches to the switch I put my fuse?

Yes, the car frame and body acts as the ground. It is one of the reasons why it is important to have a fused power wire. If the wire gets shorted out to the frame, such as pinched by a screw, it will short and if there is no fuse the wire will burn up and possibly set the whole thing on fire. Place the fuse as close to the power source (the battery) as possible. Remove the fuse when you are manuvering the wire into place to avoid accidental shorts. Most manuals would tell you to disconnect the battery while installing extra wire but I don't think that is necessary as long as you take the fuse out.

Vyger4 years ago
Whatever you do needs to be fused. You can tap off your existing fuse pannel if it has the capacity or run a wire from the battery with an inline fuse. It also depends on your cars wireing and how easy it is to get through the firewall. I added extra Cig lighter plugs to mine because I needed it for things like GPS. The origional equipment one turned off when the ignition turned it off and it was driving me crazy that every time I stoped my GPS would turn off and the laptop adapter would not charge. It's a saftey to keep the battery from being drained but I wanted the power. Also the OEM one was fused pretty light and it blew when I plugged in the laptop charger. So I ran a fused wire from the battery, through the car firewall under the dash to the new plugs I put in. Now I have all the power I could ever want. I suppose I should have done and instructable on it, Oh well.

Black to ground red to switch, and switch to battery positive.