adding a siren to factory alarm?

To use the instructions I gave, you need to find the horn.  There will only be one wire going to it.  Cut that wire.  Connect the horn to terminal 87 of the relay.  Connect the truck end of the wire to terminal 30.  Connect your siren power wire to terminal 87A. 

oh i just now got that about having to use the wires under the hood. i looked and i see 2 horns side by side. im assuming a low and a high? anyways, both wires going to each look to be GREEN/ pink stripe and bluish gray/pink stripe. which to cut and do i need to do both horns?

If you can not trace the wire back to where the 2 horn wires join each other, then yes you will need to do each horn.  You only have to power the siren from one relay.

yea i figured. i hardly have enough room to look for any wires going up to the horns. starting to think of saying the heck with it lol. any idea what the wire color would be? how do i link the 2 relays together?

No idea of the color.  Just follow the instructions for each horn.  You only need to power the siren with one or the other relays.

well now another problem arose. i install an HID headlight kit earlier today. now that LED scanner which i had working per your instructions stays on constantly....almost like its stuck shut/open. when i flick/tap it with my fingers it almost goes out but stays on? i also believe i need to wire in little resistors in the HID positive and negative leads cuz i have flickering. could this be anything to do with the scanner staying constant?

5 pin relay:

86 accessory/ignition(only power when ignition is on/run)

85 ground

30 constant power(ran out to direct off battery)

87A   LED positive wire

LED negative wire to a ground

like i said, it was working great until earlier today when i was messing around with that horn mod and HID kit install.

If it is staying on all the time, 86 has to have constant power applied. Where did you get power from? When you installed the lights, did you blow or move any fuses?

no, didnt blow any fuses or move any. ill double check the relay but im 99% sure 30 is getting constant power because thats the one i ran a wire out to the battery for positive.