Hi guys, I'm looking through my alarm installation manual and noticed I can add the stock horn along side with the siren. It says,

The Light Brown wire is pulsed ground output designed to activate the vehicle's existing car horn system in place of or in addition to a siren sounding device. Connect the Light brown wire to the negative trigger wire on the vehicle's horn relay. WARNING! Maximum output of this wire is 300mA. Horn systems requiring positive voltage or more than 300mA to trigger the horn relay will require an additional relay to increase current capabilities.

I'm wondering if my 98 Civic EX horn is under 300mA and is it a negative trigger? If so, I was looking under the hood at the horn and was wondering if I could route this brown wire through the engine bay and before the horn, cut off some insulation and tap in to the stock horn wire?

 

Nope, you need to wire a relay. Read here http://www.the12volt.com/relays/relays.asp

I have done this several times, its real easy.

 

Pretty sure a 98 Honda Civic horn is relay controlled, easy enough to check, find blue horn lead in steering wheel harness, use a jumper lead to supply a ground to the lead, fold back all but one strand of the jumper lead, supply a ground to the blue lead using only one strand of the jumper lead, if horn honks without burning, [blows like a fuse] the one strand of jumper lead, the horn is relay controlled and no other relay is needed. 94

 

Thanks guys!