siren chirp when turning off ignition
Printed From: the12volt.com
Forum Name: Car Security and Convenience
Forum Discription: Car Alarms, Keyless Entries, Remote Starters, Immobilizer Bypasses, Sensors, Door Locks, Window Modules, Heated Mirrors, Heated Seats, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=104407
Printed Date: May 18, 2024 at 9:47 PM
Topic: siren chirp when turning off ignition
Posted By: agito
Subject: siren chirp when turning off ignition
Date Posted: May 01, 2008 at 8:05 PM
Hi everyone, I just finished rewiring a few more sirens using a relay. But now whenever I turn off the ignition, it gives a slight chirp. Any ideas on how to stop this feedback? Thanks Ken
Replies:
Posted By: dtk1
Date Posted: May 01, 2008 at 9:43 PM
can you give us more information how you wired up the relay
Posted By: agito
Date Posted: May 01, 2008 at 10:05 PM
sure thing, I have my siren output on relay contact 86, contact 85 is grounded, 15amp fused positive from ignition to contact 30, and contact 87 goes to my sirens.
Posted By: dtk1
Date Posted: May 01, 2008 at 10:31 PM
your using ignition as your output power source ? try using constant other wise the relay looks perfect how many sires are you using?
Posted By: agito
Date Posted: May 01, 2008 at 10:49 PM
sorry i just checked its on a constant not ign. There's 4 wires from the relay. I tried moving to the battery directly and it did the same thing. I'm thinking the siren output is putting out some noise. Would a small resistor help?
Posted By: dtk1
Date Posted: May 01, 2008 at 10:54 PM
try unplugging the relay and see if the siren chirp connecting it directly to the output of the brain. and see id it chirp
Posted By: Mike M2
Date Posted: May 02, 2008 at 6:56 AM
You could also try putting 85 to your armed output(the starter kill wire) so that it won't engage the relay unless it's actually armed....
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Mike M2
Tech Manager
CS Dealer Services
Posted By: KPierson
Date Posted: May 02, 2008 at 10:12 AM
Did you put a diode across the coil of the relay? I doubt the siren output was designed to drive an inductive load. However, I'm not sure how not including a diode would cause it to blip like that, but I would still make sure a diode is installed. ------------- Kevin Pierson
Posted By: howie ll
Date Posted: May 02, 2008 at 10:48 AM
Don't know where the poster is but here the Cat I alarms with passive immobilisation will sometimes do that.
Posted By: agito
Date Posted: May 03, 2008 at 12:58 PM
Thanks for the ideas guys KPierson wrote:
Did you put a diode across the coil of the relay? I doubt the siren output was designed to drive an inductive load. However, I'm not sure how not including a diode would cause it to blip like that, but I would still make sure a diode is installed.
Kevin, I was thinking the exact same thing last night regarding the inductive load. Would putting a small amount of resistance help with the diode? and which direction should the diode be installed? Thanks
Posted By: KPierson
Date Posted: May 03, 2008 at 5:06 PM
No adding resistance won't help - the relay is already adding resistance to the output - if you add too much resistance you will limit the current/voltage to the point the relay will never energize. Adding a small amount of resistance won't do anything. The stripe of the diode should face the siren output of the alarm.
The non striped side should face ground. ------------- Kevin Pierson
Posted By: i am an idiot
Date Posted: May 03, 2008 at 6:20 PM
dtk1]t wrote:
y unplugging the relay and see if the siren chirp connecting it directly to the output of the brain. and see id it chirp
Have you tried this yet? I am willing to bet that the alarm is sending out a chirp to the siren when the ignition is turned off. If it is you can fix this problem with a simple delayed relay diagram from this site.
Posted By: KPierson
Date Posted: May 03, 2008 at 6:44 PM
i am an idiot wrote:
dtk1]t wrote:
y unplugging the relay and see if the siren chirp connecting it directly to the output of the brain. and see id it chirp
Have you tried this yet? I am willing to bet that the alarm is sending out a chirp to the siren when the ignition is turned off. If it is you can fix this problem with a simple delayed relay diagram from this site.
If thats the case wouldn't it have chirped before he added the relay? The first post makes it sound like everything was working fine until he added the relay, now it chirps. ------------- Kevin Pierson
Posted By: i am an idiot
Date Posted: May 03, 2008 at 7:49 PM
I am still trying to figure out what the diode is going to fix. Something is telling the relay to energize briefly, the lack of a diode is not making it energize. The diode will only kill the spike created when the electrical field collapses when power is removed from the coil.
Posted By: KPierson
Date Posted: May 03, 2008 at 8:51 PM
The diode probaly won't "fix" anything, but if he wants the siren output to last a long time it would be a good idea to add one. The collapse of the coil has the potential to destory the transistorized siren output considering the siren output wasn't intended to drive inductive loads.
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Kevin Pierson
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