alarm siren replacment

Good day Just before falling into action,can I cut out my existing alarm siren and link up an aftermarket horn if I need more noise? The alarm siren output sends a negative signal to the siren.just correct me if I'm wrong.86 Pos,85 neg output of alarm,87 12V supply fused,30 12V to horn.will this work or will the ouput be too low to engergize the coil of the relay?Do it once,do it right - This means no short cuts. You never get paid twice for having to do the job twice because it wasn't done right the first time.

Should work out fine. Diode (1N4004) across 85 and 86, band to 86 to protect the alarm.

Thanks howie.do you perhaps have a diagram of the diode connection?Do it once,do it right - This means no short cuts. You never get paid twice for having to do the job twice because it wasn't done right the first time.

No I described it, look in the relay section.

Hi howie,please view my roughly drawing.this is if I use the existing car horn.please guide if this is correct.Do it once,do it right - This means no short cuts. You never get paid twice for having to do the job twice because it wasn't done right the first time.

Look at the bottom diagram on this page:- https://www.the12volt.com/doorlocks/page3.asp#4w

There are some photo's of the coil quenching diode addition to a relay harness in this R/S Pictorial :

https://www.the12volt.com/installbay/forum_posts.asp?tid=133810

Soldering is fun!

Thanks kreg and howie.I understand now.anode goes to negative coil and cathode to positive coil.Do it once,do it right - This means no short cuts. You never get paid twice for having to do the job twice because it wasn't done right the first time.

You do of course realise KM that we probably use the same source and parts for our relay set-ups? Even down to the shrinkie over the diode?