Getting a +12v out when alarm sounds?
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=15102
Printed Date: September 16, 2025 at 7:56 PM
Topic: Getting a +12v out when alarm sounds?
Posted By: Micky2002
Subject: Getting a +12v out when alarm sounds?
Date Posted: June 18, 2003 at 10:40 AM
Hi I've searched on the net to no avail so thought i'd post here, also asked the guys who installed me alarm, they don't know either, but I know it can be done. I'm trying to get a +12v constant when the alarm is triggered. I have a UK spec Clifford Concept 500 w / remote start. I believe this to be the correct wiring diagram https://www.clifford.com/guides/wiring/concept50x_wiring.pdf but this could also be it, don't think so though https://www.clifford.com/guides/wiring/concept50_wiring.pdf I'm guessing to get a 12v constant I'd have to wire in parallel to the yellow siren wire, but i'm not too hot on hacking up my alarm just to see if i was right :) Any help would be appreciated ps. If anyone wants to know what it's for, it's to trigger a relay to a homemade pager device i've made.
Replies:
Posted By: chasesaccessori
Date Posted: June 18, 2003 at 11:10 AM
put a relay on the siren wire that gives you 12v. The siren wire gives you ground when triggered, so connect that to 85, power 12v to 86 and 30. Your needed 12v will be on pin 87. https://www.the12volt.com/relays/relays.asp
Posted By: Micky2002
Date Posted: June 20, 2003 at 12:59 PM
Tried it, didn't work, both sides of the red power wire were positive, instead of only one being positive. Think it's because my siren has a battery backup when the power is cut to it. Any other ideas? Also, the wiring diagrams i posted up there are wrong :(
Posted By: djfearny2
Date Posted: June 20, 2003 at 1:50 PM
test wires and determine which wire on alarm is siren wire. this wire will show constant 12 votls when the alarm sounds and little short voltage when you are and disarm the system. peel a little casing back on that wire and atach and tape another wire now grab a relay normal 5 pin bosch relay or equivalent. and connect the wire you just ran to pin 85.
connect pin 86 to ground
pin 87 to constant 10 amps fused wire.
and pin 30 to output to whatever you want to give 12 volts too.
pin 87a not used in this setup.
-------------
Jon
Installer/Help Technician
---coral springs florida---
mecp certification is not always needed. I have it and it has not helped me out at all. my experience out shines it.
Posted By: Micky2002
Date Posted: June 20, 2003 at 2:39 PM
I'll give it a try now, this will work with a normal 4 pin relay aswell right? since 87a aint even used.
Posted By: Micky2002
Date Posted: June 20, 2003 at 2:55 PM
Doesn't work :( As soon as I connect the ground, the relay turns on, no matter if the alarm is on,off, sounding or in valet mode. Any more ideas?
Posted By: chuck_tempe
Date Posted: June 21, 2003 at 5:11 PM
two red wires? from the clifford diagram there is suppose to be a yellow wire that provides a ground to trip the siren. what you could do also is use the parking light flash to trigger your pager. you should have a positive trigger input on the module. if you don't, you will have to install a latching relay to make it work. https://www.the12volt.com/relays/page5.asp
Posted By: Micky2002
Date Posted: June 21, 2003 at 5:36 PM
The diagrams I posted up there are old, and not for my alarm :( And they don't publish current alarm diagrams so mine is not on there and shouldn't be anywhere on the web :( When I said 2 red wires, I meant both sides of the red wire if ya know what I mean. As in, there was 1 red wire, I cut it in half, then there were kinda 2 red wires. Both sides were positive (cos of the smart siren). If I installed it on the parking light flash trigger, wouldn't it operate the pager everytime I armed/disarmed, went to valet mode etc etc? A guy from Directed (they own clifford) said my alarm could do it, but he can't tell me (cos I could be a thief) and to ask my installers. They don't know how to make it work either. And I don't like the idea of paying em £50 just to solder one wire. A way they suggested to do it would be to wire it to the door sensors, but that would then operate the pager everytime I opened the door :( Surely this can't be that hard for a pretty top end alarm ffs 
Posted By: balumnia
Date Posted: June 22, 2003 at 9:22 PM
There should be two wires coming out of your siren. One of them is power, one is ground. One of them has to be switched by the system's control unit, otherwise the siren would be sounding all of the time. Test the two wires with a DVM or test light. You should find that the wire you have been working with that goes to the car battery and backup battery is a constant positive. The other wire shouldn't test as power or ground unless the siren is sounding, at which time it should test as ground. This is the wire switched by the control unit (ought to be the yellow wire coming out of the control unit, but Clifford may have changed their color codes since I used to install back in the Middle Ages). Tap into this wire and connect to terminal 85 of your relay. Connect terminal 86 to power. Connect terminal 87 to your fused power source and connect terminal 30 to the power lead for your pager. This is basically the same thing djfearney2 suggested, only adapted for a negative (ground) trigger. Your pager may react when your siren chirps on arm/disarm. Good luck!
Posted By: chuck_tempe
Date Posted: June 23, 2003 at 12:25 AM
if you alarm is close the diagram to the clifford 50x, you should have a green wire which is negative output when armed. to wire up a relay with this, connect the green wire to 85, parking light flash to 86 and 87 (87a is not used). terminal 30 would then go to positive trigger on your pager. with this setup, your pager will only go off when armed and the parking lights flashing. this is not a constant 12 volts, but it does provide you a (+) trigger.
Posted By: Micky2002
Date Posted: June 23, 2003 at 12:22 PM
Hmmm... Since I already blew my alarm up once (only a fuse, but took me ages to find it and couldn't get to work or lock doors  ) I'm gonna take it back to the installers and suggest that they do the things listed above. since then it'll be under warranty and the like, cheers guys :)
Posted By: chuck_tempe
Date Posted: June 23, 2003 at 10:58 PM
i hope those guys won't charge you too much. don't get discouraged too easy, that's how we all got started in this business. a warranty is always nice to have. too bad they are just too 'secretive'.
Posted By: Micky2002
Date Posted: June 24, 2003 at 10:36 AM
Probably won't charge me too much, just take em about 2 weeks 
Posted By: philaf
Date Posted: June 28, 2003 at 7:46 PM
perhaps you're looking for the wrong signal? i may be wrong, but i believe clifford sends a +12v to the siren, not a ground.
Posted By: Micky2002
Date Posted: June 29, 2003 at 2:54 AM
I've given up tryin to do it myself now, when I get off my lazy ass and get some money i'll be calling the installers :)
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