97 tahoe ultrastart siren/horn

im installing a pretty cheap alarm/remote start called ultrastart on a 97 tahoe. everything is connected and working except the siren. The alarm didn't come with a siren so i had to connect it to the factory horn. The alarm's horn/siren wire sends out a negative pulse but only like 300ma, not enough to push the factory horn. I connected it through a relay putting terminal 86 to the alarm siren wire, 85 to 12v constant, contact 87 to ground and 30 to the factory horn. I did this thinking the relay would do the work but the relay didn't even click. How can i connect the siren wire to the factory horn or a siren that i might find even though the wire sends a weak pulse?? THANKS IN ADVANCE.

You can always get any type of siren as all sirens have two wires which are ground and power.  The problem that you may encounter when it comes to connecting the siren output wire to a horn is that it is a constant pulse.  I dont have experience with ultrastarts but if it has a programable feature in which  you can change the constant output to a pulsed then you can use it. My question for you is did you use the black wire at the column?  It is a negative trigger.  Make sure you are using the right one.  And according to your relay setup, it appears correct.  Try using another relay.

yea i use the black wire at the column and i'm pretty sure its dat one because i tapped the wire to metal and the horn sounded so i'm 100% positive. I'm going to try to connect it to the siren hopefully it works, but would i still need to use a relay to connect it to the siren??:

Connecting it direct may give you a result but beware with what you did earlier with tapping that wire to ground.  Always use a multimeter for testing.  Lucky it wasnt something that was had positive.  Could of shorted something out on your car.  Also, like I mentioned earlier make sure it doesnt give constant ground as it will simulate a person holding down the horn.

lol yea the horn wire tapping metal was by mistake, but i'm going to connect it to a regular siren without a relay hopefully that works, thanks a lot

what model alarm? 440? 600? Siren wire is a positive output from the WHITE/ blue wire, and is programmable for horn honk output and should have come with a siren, they all doMy rifle is my friend...