Hey guy, i want to install an air horn on my 91 civic, I got the kit off ebay and among the things in the kit was a relay. Is this needed for installing on my car? i just assumed i could cut the original horn wires, wire the compressor and it would work. I've never worked with relays before, so even though there is a pictured wiring diagram included, im still not sure how to use it or if i even need to. Anyone got any advice?

thanks in advance-

 

the relay could be used for a couple of things. 1st it could be used to turn the compressor on only when the ignition is on. you don't want to draw a ton of current from an ingniion lead. And wire in up like this, 85 to an ignition lead, 86 to ground, 87 to the battery, and 30 to the compressor. 2nd it can be wired up for the horn switch.. Again you don't want to draw alot of current from the horn switch to open the solonoid so assist it with a relay. 85 to horn wire, 86 to 12v source if horn is negative trigger or ground if it is positive trigger, 87 to 12v source, and 30 out to the solonoid. Also mount the solonoid as far away from the tank as possible so you have just that much more air in reserve.