Printer Friendly Forum Posts - Ground When Armed Output Purpose?

Hey everyone, I'm in the middle of installing my viper alarm (5002) on a 2000 s2000 and will probably have TON's of question for the install... My first question, one of the wires on the alarm is titled "H1/12 Orange(-)500 mA Ground-When-Armed-Output" ---> I'm not doing any remote starts, or anything like that, would I still need this? what exactly is its purpose?

Thanks for the clarification!

I am sure it has several purposes, but the one that comes to mind is for an aftermarket LED array called a scanner.

Generally do not need that wire unless you are adding some type of accessories. I used mine for a window roll up module. For a basic alarm install however and adding no additional components or sensors, you will not need the ground when armed output.

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It Hz

actually, i'll be adding 2 additional sensors.. ummm, tilt and radar... they plug right in to the brain....

so am I right to assume that I would need to wire this then (ground when armed output)? Do i just simply bolt this wire to the car's chassis? sorry for the noobie questions, appreciate the help

I have a very similar question with a Clifford Arrow 5. I have the same wire orange(H1/17 on my harness) and for the same purpose-ground when armed. I had assumed that I simply leave this wire alone, until I add an accessory.

Yea that wire is for a starter kill. If you wire that up, as long as the vehicle is armed, the vehicle cant be started. Another thing you could use that wire for is for adding sensors. Sensors get power reguardless if the vehicle is armed, disarmed, or even being driven. So you can actually wire that ground when armed output to the sensor's power wire. Thus the sensor will only be powered when the vehicle is armed. It can save battery power though those sensors dont draw alot of current anyways. You will just need to remember that the ground when armed output is a negative trigger and the sensors power wires are a positive polarity. You will need to have a relay to convert the polarity. I have 2 sensors; a tilt and motion sensor, that will have their power running to that ground when armed output wire. I will be using 1 relay to convert that wire to positive then. That single wire will power both those sensors. Just remember that the ground when armed output is only a 500ma current. Those sensors need alot more than 500ma. So you install that relay. The current from that wire will trigger the relay. The relays power wire will then in turn power both those sensors. Hope some of this helps you and whenever in doubt, simply ask us.

Thank you to everyone. I like this forum alot, its very noobie friendly!

audioman2007 wrote:

Yea that wire is for a starter kill. If you wire that up, as long as the vehicle is armed, the vehicle cant be started. Another thing you could use that wire for is for adding sensors. Sensors get power reguardless if the vehicle is armed, disarmed, or even being driven. So you can actually wire that ground when armed output to the sensor's power wire. Thus the sensor will only be powered when the vehicle is armed. It can save battery power though those sensors dont draw alot of current anyways. You will just need to remember that the ground when armed output is a negative trigger and the sensors power wires are a positive polarity. You will need to have a relay to convert the polarity. I have 2 sensors; a tilt and motion sensor, that will have their power running to that ground when armed output wire. I will be using 1 relay to convert that wire to positive then. That single wire will power both those sensors. Just remember that the ground when armed output is only a 500ma current. Those sensors need alot more than 500ma. So you install that relay. The current from that wire will trigger the relay. The relays power wire will then in turn power both those sensors. Hope some of this helps you and whenever in doubt, simply ask us.

I may need to start my own thread for my install. I've got an immobilizer harness with 3 black wires (H2/1,H2/2,H2/3) for normally open or normally closed circuits.

The ground out when armed is only for starter kill relays and shouldn't be used for anything else. I wouldn't recommned using it to power a relay to supply power to any sensor. If you use it for this purpose the relay will be energized when the alarm is armed. The resulting draw of around 150 ma will kill a vehicle's battery in a day or so. Sensors should always be hooked up as the instructions say. They are almost always hooked to battery and constant ground. They only draw a couple of ma or so. Sensors also tend to trigger right after they are powered up, so it could cause false alarms when arming. It is important to understand that when using the ground when armed output it should only be connected to one side of the relay coil (Terminal # 85). The other side of the relay coil (Terminal # 86) MUST be connected to an ignition source and NOT to battery. This way the relay is only energized when the alarmed is armed and only when the ignition circuit is powered.

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sparky

[QUOTE=sparkie] The ground out when armed is only for starter kill relays and shouldn't be used for anything else. I wouldn't recommned using it to power a relay to supply power to any sensor.

the ground when armed is not only for starter kills, there are plenty of
things that this wire is required for like starter kill, window modules,
scanning led's, tilt sensors just to name a few.

My instrustions for my tilt sensor's power wire says to install it to a constant 12V source OR the positive when armed ouput. Now since my alarm has a ground when armed otutput, I would need to install a relay to change polarity. Another thing, sparkie said that connecting it to the ground when armed output might draw too much current and drain the battery, which might be true BUT explane to me whats different about connecting the sensor to a constant power source? When a sensor is connected to a constant power source, that sensor will have constant power to it reguardless if its armed or not. My shock sensor that came with my alarm plugs right into the brain. I will have my car disarmed and when I tap on the sensor itself, the LED's light up. I kinda hate that because I only want my sensors working when the car is armed.

it will not drain too much, you have nothing to worry about. what other wires are on your tilt sensor besides 12v when armed?

trigger and ground. Your battery will still lose the same amount of "juice" reguardless if the sensor is connected to the positive battery terminal or the ground when armed ouput.

that sensor with or without a relay is not gonna drain your system

i totally disagree with the statement that this wire is only for starter kills. u can use this wire for multiple things, such as starter kill, window rollup when you arm the car, scanners and more. the main thing to keep in mind when using this wire is to use diodes. what you would do is cut the wire in half and depending how many other things your planning to use when the car is armed is: say you have window rollups and a scanner, you use a diode with the white line facing the brain. then you connect the orange wire from the window rollup module and the scanner and join it with the orange wire from the alarm towards the brain side of the diode. then you use pin (85) of the starter kill and connect it on the other side of the diode(this is so the starter kill relay does't feed back through anything) and then pin (86) of the starter kill to ignition. doing all of this will make it so and only so when you arm the alarm the windows will go up(in case by mistake you or the passenger left one of the windows down)and then the scanner(s) will light up and the car will not be able to start with the key or another tool while the alarm is armed.

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alarm king

Yea you can use the ground when armed output to do starter kill PLUS anything else you want. You just need to use a relay. For instance use a relay for the starter kill. You would splice the ground when armed output into 2 wires. You would run 1 to the starter kill relay. I agree and would use a diode. Better to be safe than sorry. Then the other spliced wire would go to another relay which would be for sensors, window modues, led's. Wait. hmmm. So I could add another LED to my system? I wanted to do that. The alarm I have has the LED at the antenna. I wanted to keep that intack but add another LED. So I could simply use the ground when armed output run it to a relay to change the polarity, then run it to the power of the LED correct?

The extra LED I got with my alarm has 3 wires: Constant 12V, ignition, and ground. Now since I will be hooking the LED up to the ground when armed output (using a relay to convert polarity) do I just run both the LED's constant 12V and ignition wires to that relay or do I run the constant 12V to constant 12V and run the ignition wire to the relay? I only want the LED to work when the vehicle is armed and no other times.

I am sorry for starting such an uproar. Yes, I should have mentioned that you can use the grd out when armed for other things. My intent was to bring to light a common problem that some inexperienced installers make. Alarm sensors don't draw much current and it makes no difference if they are hooked up when the alarm isn't armed. They won't do anything unless the alarm is armed. The big problem that I have seen many many many installers make is to use it to ativate a relay which has the other side of the relay coil connected to battery. I have seen many upset customers and angry people after it is discovered that the battery was killed because of an improperly wired relay. The other factor that needs to be addressed is that transistorized outputs are rated for certain current demands. Using the output for too many devices can overload the transistor and casue it to fail. Not something you want if someone does try and hot wire the car.

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sparky

I totally understand sparkie. People on here that ask questions and dont know much when we go and answer them, you should try and keep it as simple as possible for them so they dont wire it wrong and possibly cause a big problem, thus blaming it on us. But then on the other hand, lets also add the fact that you can do these things with that relay, for those of us who do know the basics and wont mess anything up. But one thing sparkie, could you possibly answer my question about the LED I posted above? The LED I have (thats not installed) has 3 wires. One is for constant power, one is for ground, and the other is for ignition. I want to run this LED off the ground when armed output so that the LED ONLY works when the car is armed. Now I think i tested this before and the only time the LED would work is when I had both power wires connected to the battery positive (so therefore both need to have power to them inroder for it to work). Now does this mean I run the constant 12V wire to constant 12V and run the ignition wire to the ground when armed wire (using a relay to convert polarity) or can I run both wires to that relay for the ground when armed wire, oor does it even matter? Thank you in advance. Oh and we arent trying to stir anything up here. We just want to get as much useful info out there to help everyone else. Thanks.

I just tested out that LED. The only time it lights up is when I have the black wire grounded, and the red wire to constant power. As soon as I touch the ignition wire to the battery positive, the lights go out. So does that mean I ignore the ignition wire all together and just wire up the red wire to the ground when armed wire (using a relay in between)?

Try hooking the constant power to constant power, the ground to ground, and the ignition to the (-) when armed wire.

Most ignition systems rest at ground, so when the igntion isn't on it is grounded. If this doesn't work, then try hooking the constant up to constant, don't use the igniton wire, and wire the ground to the ground when armed.

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Kevin Pierson

Ok I just tried that. I touched the constant to the battery's positive terminal and grounded both the ground and ignition wires to the negative bettery terminal, and it worked. BUT, it will also work it I dont use the ignition wire at all. But if I touch the ignition to positive, it wont work. So does that mean that If I wire it up exactly how it should be, then when the vehicle is on, 12V will go through that ignition wire causing the LED not to work. Then when I turn the vehicle off, that ignition wire then is grounded thus making the LED light up? But this wont work with how I want to do it. I want to use this with the "armed output" which in my manual says that when I arm the alarm, that wire gets grounded (which is for starter kill). So what I would do is run that "armed output" wire to a relay. That relay would change the polarity from negative to positive. I would run that relay then to the red constant power for the LED. The yellow ignition wire I would leave disconnected, and ground the LED's black wire. This way the only time the LED will work is when the alarm is armed. Would this setup work?

You don't need the relay - just wire the "GROUND when armed output" to the GROUND terminal of the LED. Don't connect the ignition wire at all, just tape it off.

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Kevin Pierson

The LED is designed to be both a LED for an alarm and a fake alarm. I used to sell LED scanners like this. There are a few LED's wired into a small circuit that can flash in different patterns and rates. If you want you can wire it up with battery, ground and ignition. This is the fake alarm method. When the ignition is off the LED flashes and makes people think you have an alarm. If you use it for an alarm system status indicator then only hook up the battery wire to it and the ground for it can go to the alarm's ground out when running wire. The drawback to this method, is that many alarms use the LED that they come with to flash a specific sequence to inform you of something. They can tell you if it is in valet mode, whether it is passively arming or whether or not the alarm was triggered and which zone was violated. You can also just bury the LED that came with the alarm in another hidden area in case you still wish this info.

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sparky

Yea, well with my alarm, my LED is with my antenna. I have the antenna mounted on the windshield under my rear view mirror. I will leave that LED in tact. But that LED is small and hard to see sometimes at night. Thats why I wanted to have another LED. This LED wont do the stuff you mentioned before, the LED that came with the alarm will do that stuff. I just want this other LED so that people can see it alot better. So would I wire it like I said before, using just 2 wires, the red wired up to the relay for the armed output and then ground the black, or should I run the red to constant 12V and run the ground wire to the armed output?

Sorry Kevin, I wasnt ignoring your post. I just looked at the very last post there was and did not see yours till now.

Run the red to a fused constant and the black to the ground out when armed. Using the brighter LED is a good idea. It is your best deterent to convincing a thief to find an easier target. Mount it where it is visible from either side of the vehicle.

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sparky

Ok 1 more thing. I have 2 sensors that I want to hook up but I only want them powered when the car is armed. To do this I would need to use that exact same wire the armed output wire. I would have to use a relay to convert polarity ofcource. Now since I want to do that also, can I just connect the constant power to the armed output and just ground the black wire? I mean i would need to use a relay for those 2 sensors anyways, wouldnt it just be easier to run the LED into the relay as well?

You do NOT want to use a relay on the (-) when armed output, it will kill your battery.

Do the same thing you did for the LED, connect the (+) of the sensor to (+) voltage and connect the GROUND to the alarms "GROUND when armed output".

Constantly powered relays on "ground when armed outputs" are BAD!!!!!!!!!!!!!!!!!!!!!!!!

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Kevin Pierson

I second that. This is what I have been talking about. There is no good reason to wire sensors so that they only have power and ground when the alarm is armed. Simply wire them to the alarm like they are supposed to be. Sensors can false if they are powered up at the same time the alarm is armed. Don't complicate things. Your alarm ignores any sensor trigger until it is armed.

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sparky

So then I just shouldnt wire the sensors to that wire at all, or can I? If not, then I would wire the sensor's red wire to constant power, and ground the black wire. But that sensor will have power all the time then.

posted_image

I wanted to wire the relay like this. The - trigger would be the ground when armed output wire. Pin 87 would go to the LED's power, to the sensors power as well. That relay wouldnt be energized unless pin 85 got grounded, correct? Plus when I go and arm my car, my LED there at the antenna doesnt start blinking (showing that the car is protected) until 10 seonds afterwards. I am not disagreeing with you's at all. I will do what you say, but just want to know if my method will work, plus know alittle more about this stuff.

That method will technically work, but the 200mA current draw from the relay coil being energized while your alarm is armed will kill your battery in 3-4 days of sitting.

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Kevin Pierson

what kind of sensor is it that you are tryin to wire up?

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alarm king

The sensors I will eventually install will be a microwave sensor (which I probably wont install) and a tilt sensor. So what you are saying is I should wire the constant power wires from the sensor(s) and from the LED to a constant power wire thats running to my battery. Then wire their grounds to the armed output "ground when armed" wire?

Connect the sensor's battery wire to a fused battery source. Connect the sensor's ground wire to a good ground. Forget the ground out when armed wire. Use it for a starter kill relay if you want. Connect the sensors trigger wire to one of the alarms trigger inputs. If you have 2 sensors and only one trigger input, install both sensor trigger wires to the one alarm trigger wire. Install a diode inline in each sensor trigger wire before you join the wires together. Have the band of the diode facing away from the alarm. Forget using a relay. It is not required and will only cause a drain on the battery. The LED for your alarm may have it's own connection out of the alarm. Not all LED's can take 12 volts and usually the alarm has resistance built into the LED output to send the LED the correct voltage. Failure to do this will cause your LED to blow up.

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sparky

Ok, I will wire the sensors how you said sparkie, but 1 question. Since those sensors will be powered all the time, will it drain my battery? Also dealing with the LED, I am not talking about the LED that came with my alarm. That LED plugs directly into the brain and I will be leaving that alone. But that LED is small and hard to see from outside the vehicle. The LED I bought says to connect the power wire to a constant 12V source. So therefore it can handle 12V. I went out today and hooked that LED's power wire to a constant 12V (connected it to the battery + to test it). I then ran the LED's ground wire to the armed output from the alarm. As soon as I armed the system, the LED lit up. As soon as I disarmed the system, the LED turned off. So obviously this setup will work. I want to mount this LED on the middle, front part of the dash at the windshied. The LED that came with my alarm is mounted on the windshield right below the rear view mirror and faces down at the center console making it hard to see.

The sensors draw so little current, it would take a month or more for them to discharge your battery. You can wire the additional LED as you mentioned without any issues. You should be good to go now.

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sparky

Hi
The "ground when armed" wire can be used for a power window roll up module,,or a starter kill
That's all I can think,I'm sure the other guy's on this site know more
Hope this helps a little

Is it possible to overload the ground when armed output by having too many ground wires running to it? Mine has 500ma output.

from what I understand(please correct me guys)the 500ma signal is only to run a realy for a true ground(500 ma is for a relay)I had tried to use this for a security defeat(factory)and it didn't work all the time, but when I used it to run a relay directly to ground it worked
but then again,I'm not as knowagble as these guys
these guys are great
THANX AGAIN GUYS

connecting too many devices to the ground output will for sure burn the output. the output eventhough its rated for 500mA, a relay draws about 150mA to energize. that can drain a battery over a few days, but yes connecting too many will overload it

Theoretically if the alarm is designed correctly the only thing that will happen is you won't have enough current to power your devices. If the tolerances of the compoents are out of spec, or missing current limiting resistors (to save cost) then you can burn up the transistor output by putting too much load on it.

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Kevin Pierson

Ok, I need someone to help me out with this.... I went and ordered a LED. It has 4 wires, 3 of which I will be using. The orange is to be connected to the ground when armed ouput from the alarm (which is what I will be using). The red is for constant power. The black is for ground. The white wire (wont be using) is to connect to other LED's for a network of them. Now, when I run the other 3 wires as stated above, I can program the LED BUT when I arm the system, nothing happens. When I run the black wire with the orange to the armed ouput, it then works when I arm it. I have this same problem if I run the black and red wires straight to the battery and then orange to armed output, I get nothing. So could I simply just run the orange and black wires to the armed output? This is the ONLY 2 wires that will be on that armed output wire, nothing else. Its rated for 500Ma. The LED lights up perfectly fine with no dimming or any problems. Would this work or would this ruin that output?

be safe and use a relay. just run he black and orange together. It could be that your orange is ground and the black is your switched source.

You really can't use a relay here as it will kill the battery. The LED strip should be very low current, otherwise, it too would kill the battery. I would guess that you would be OK just hooking it up to the ground when armed wire.

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Kevin Pierson

Ok well give your input on this..... When a "such and such" output is rated for 500Ma, that means it can put out 500Ma. So given that, its saying that it puts that out and nothing more. So if a unit needs lets say 800Ma to operate, then the output will put out its 500Ma and since the unit needs 800Ma, it either wont work or will be dim, correct? So I actually cant burn it out if its only able to put out 500Ma. Just correct me if I am wrong. I wasnt going to use a relay anyways because you's told me that it will kill the battery. I just dont think that those 2 wires need more than 500Ma. I mean that means that these car alarms would have more output for those reasons.

It actually depends on several factors. If the alarm is of high quality and engineered to tight tolerences then the alarm will only output 500mA.

If it is a cheaply built or poorly tolerenced unit then when you try to pull 1000mA from the output, it will deliver 1000mA at the cost of overheating / stressing the internal components (namely the Darlington transistor output). This could cause the output to fail quickly.

On the other hand, 500mA in a car is a very large amount of current. Unless you go crazy you should have no worries on overloading it. Your LED array is probably no more then 25mA when it is on. Other sensors or inputs would be even less, typically under 10mA. The only thing of significant load that I could ever see being hooked up to the (-) when out wire is a relay, which will draw about 150-250mA. Again though, this load, when on constantly, will kill the battery in 3-4 days of sitting.

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Kevin Pierson

Well the LED needed a 15 amp fuse if that means anything

lol.

A 15A fuse for an LED????? That would be more current then most high powered head units. It may be 15mA. :)

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Kevin Pierson

Audioman, if you need more current capacity, the following device will easily allow your 800 ma device to work. I am sure Radio Shack has a suitable part available. If there is an electronics parts warehouse near you an NTE 332 is the device you need to get. If that is not possible for you I will find you something at Radio Shack. If you try to run the device on the 500ma output there is a very good chance that you will damage the output of the alarm. If you only need 800 ma there is no need for a heat sink on this device. If you need more or if it is heating up, you can mount it to a piece of metal under the dash. This also works on some bluetooth devices that do not provide enough current to trip a relay. posted_image

https://www.radioshack.com/product/index.jsp?productid=2062613&cp=&sr=1&origkw=pnp&kw=pnp&parentPage=search

Keven, The LED itself doesnt have a fuse in it. I installed a fuse in line. At first I started with a 5 amp fuse and it blew it right away. Then I used a 10 amp and it blew about 5 seconds. I now have a 15 amp and its fine.

I am an idiot, none of my devices are 800Ma. I just used that to try and make a point. The output on my armed output is 500Ma. How long would it take to burn up the output? I doubt having those wires run off that output will overheat it.

When I have the ground wire grounded and the orange wire to armed output, I am able to program the LED speed, but then when I arm it, I get nothing. With both black and orange being wired to the armed ouput, I cant program the speed, but the LED works when I arm the system. I just dont understand it. This is exactly how I did it... I have a relay that is supposed to run my neaon underbody lights (which I never installed) That relay used has 2 power wires since that relay is to convert polarity. I have 1 power wire splitting off to those 2 wires with an inline fuse that was 10 amps. I then spliced off of one of those wires for the LED power wire using a fuse inline rated at 5 amps. When I first installed the LED, I blew the 5 amp right away, and since I had no small blade fuses laying around I used my fog lights fuse which was 20 amps. The LED didnt work then so I thought I messed it up. So I ripped out the LED only to rip off the plug on it. I then had to use butt connectors to fix that. When I went to install it again this morning, I then blew the 10 amp fuse. I replaced that with a 20 amp and the other with a 15 amp. Thats where I am thinking the LED needs a 15 amp.