i plan to upgrade my audi alarm with adding or replace the alarm horn with 2 sirens but... i heard i need an relay to do that , is anyone who can give me more info about what kind of relay i need and a diagram so i have an ideea how to connect everything.

 

you don't have to get a relay to do it. i replaced the stupid quiet horn in mine a long time ago with a new little mini pizo siren. it works MUCH better than the stock alarm horn. there's only 2 wires to it, so i'm pretty sure you don't need a diagram. one's just the ground and the other is the live 12v wire.

 

i remember finding your post and the clip with the sound of the new siren , but i was thinking if are any changes for 2 sirens insted of one, a guy who sell the sirens on ebay said a relay is need to do the job , so i start fishing for more information.