how can i sound the horn if alarm armed

Morning All Ive had a look through the threads, cant find an answer. However, I want to remotely sound the cars horn, to warn away anyone I see near the car. I have used a accessory output through a relay to sound the horn, but this don't work while the alarm is armed The alarm I have is a Clifford Concept 470 with InteliStart Car is a 1981 Austin Mini Can anyone think of a way I can get a remote output while armed. Thanks in advance

I'm not familiar with the system you are using but does it have an unused aux output or a unused trunk release that you could use to trigger it ?If i Can't Install it    I Don't need it   Joe

Thanks for the quick reply I have used a aux output this only works while the system in disarmed I tested the trunk release and this is the same Only outputs while disarmed Cheers

The secondary horn out output yellow/white only works on full trigger. What sensors are you using with this unit. Note: Whatever I suggest won't work with the digital prox sensor if you have one installed. Assuming you've already relayed the above yellow/white to your horn, join the green wire from other sensors to the yellow white. Note if you've used a 508d instead of the digital prox then it will work but in this case you must use diodes (1n4004)in line on the greens, bands away from the yellow white.Test before boxing up.