Printer Friendly Forum Posts - wiring trunk pin switch to door trigger

I am wondering if this is the correct way to do this... I want to splice into the trunk light ground and run that to the (-) door trigger input. Run diodes on that wire and also at the door switch (which actually runs to my domelight wire. Please let me know if this is correct or not. Thanks.

2002 Cavalier

Asianwolf8000RS

Not really but it can be done. All systems I have seen should have a negative input for hood/trunk already there. But as long as you diode isolate the wires the alarm will sound when it picks up the negative so yes..it will work.

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Just as long as the (-) from the trunk is'nt present at all times..[when the trunk is closed...

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Tire Proz Stillwater Mn
High End Restyling and Comlete Repair

Well I was also thinking of doing as you said and use the hood pin wire and just diode into that wire. But I have remote start, so as long as my trunk is opened, I wont be able to remote start correct?

worse than that, if you pop your trunk while the car is running (with RS) it will shutdown

You all are thinking of the negative shutdown wire vs. the hood/trunk trigger negative input wire.

True, if you connected a negative trunk wire to the shutdown you would have a problem...but the trigger input would work just fine. On many systems the negative shutdown also functions as a trigger as well..but this is not the same thing as the hood/trunk negative trigger input..which is designed for the purpose of protecting those points and still allow the RS to function properly.

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That is why I want to use the door trigger. Now I went out in the freezing cold to try something out. I cut and spliced a wire into the black negative wire at my trunk light. I cut the negative door trigger wire (which runs to the domelight). I ran that trigger wire to the wire I spliced into the trunk light negative just to see if it works. Heres the results...... When the trunk is closed with the alarm armed, nothing happens. When the alarm is armed and I manually open the trunk, nothing happens. But when I put the 2 door trigger ends back together, then the system goes off. Now I honestly have no clue what to do. Anyone have sugestions?

obviosly you are on the wrong wire in the trunk..you need to use a DMM to find out whats going on..everything else is just guesswork.

Also again,.....you are confusing the negative shutdown wire with the negative hood/trunk trigger input. If the trunk uses a negative trigger when OPEN... tie to that wire. If the trunk trigger is positive..you need to tie into the positve trigger wire for that. Use the negative SHUTDOWN wire for the hood..it's really that simple. But regardless you need to determine the proper wire and its polarity when the trunk is open before proceeding any further. Good Luck

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Also..you never mentioned the vehicle..certain american cars used a mercury tilt sensor to turn on the trunk light..which is internal..really no good way to tap into it, the wire running to it is constant 12v positive..of no use to the alarm trigger..if thats the case you need to mount your own pin and connect it to the NEGATIVE HOOD/TRUNK trigger INPUT wire.....and once again connect the negative SHUTDOWN wire to the hood pin. The doors seem fine so leave those connected as is.

Now post what kind of car it is and perhaps we can tell you the color and polarity.

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Well I did something wrong because I hooked the door trigger wire up to how it was before. Now when I open either door, the dome light doesnt come on at all.

I dont know what happened, but now my domelight works when I open and close the door, but when I arm the car, and manually open the door, the alarm wont trigger, yet my domelight comes on.

if you open the door and the domelight comes on..but the alarm doesn't ring..you are not connected properly to the trigger wire or....the alarm has bypassed that zone because you are checking it too many times in a row. If thats the case turn on the ignition after each time you check it.

BTW..are you using a meter???... because if you were you would know why things are not working right..so be sure to use one. Thanks

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Oh..and on your vehicle the trunk wire is black at the light and should throw a negative when the trunk is open. Connect the HOOD/TRUNK negative instant trigger INPUT wire to that..close everything up...arm it...wait 20 seconds..and open the trunk with the key...the alarm should sound....now remote start the vehicle with the trunk open..you will find it will remote start just fine if everything else is correct.

Use the negative SHUTDOWN wire for the hood pin for safety. If the vehicle does not start with the hood closed you need to adjust the pin. Make sure if the system has a neutral safty switch wire that you ground it..that is safe for your vehicle but it won't start at all with the remote otherwise.

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Well the thing is that i did use the black ground wire at the trunk light. I knew that was the wire when I cut it, the light didnt work. But I wanted to test it first before I ran diodes, so I cut the door trigger wire which I had running to the domelight wire. I then ran the trunk wire I spliced into the black ground wire, and ran that to the door trigger wire. I closed everything and armed it. I manually opened the door. The trunk light came on but the alarm didnt sound. Ever since then, I cant get anything to work

Just as master5 said, you need to test the wires with a dmm......just cutting 1 wire at the trunk light is not gonna tell you anything.....either wire you cut will shut the light off. Whats not working now? Domelight? Might have a blown fuse now. Could of smoked the door trigger input on the alarm.

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Well the trigger inputs of the RS system should be able to handle positive or negative without burning up..after all those wires will typically see the opposite polarity depending on the door being open or closed.

But yes..when you state "I can't get anything to work" all that tells me is you are not checking the basics with a meter..main power, ground, ignition and so on. Without knowing whats there you can't really troubleshoot properly...don't depend on luck or guessing. See what the meter says..it doesn't lie.

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Well i hooked everything up to how it was before I started cutting wires. Now, when I arm the car, everything works fine. Domelight, door locks, everything. When I manually unlock the door, the alarm sets off, just like it is supposed to. Now when I go to disarm my alarm, the siren chirps twice (as its suppposed to), but my parking lights flash 3 times. Then when I get into the car and turn the igntion on (not actually start the car), plus my service light comes on. But it will only come once, untill i arm and then disarm again. Could I have fried something?

Ok forget the last post. The entire system works fine. Here the siren is supposed to chirp twice when disarming, the parking lights are supposed to flash twice and then come on again, because I have illuminated entry delay. And the reason why my service light was coming on was because I still had the fused pulled for the horn. Once I put that fuse back in, bye bye service light. So very duh on my part. But I still want my trunk to trigger my alarm. Does anyone have any ideas at all?

Yes I have a great idea...just do what I have been suggesting all along. Using a DMM find the wire at the trunk light that shows negative 12v when the trunk is open...if you are on the correct wire it will also show 12v positive when the trunk is closed...that is normal.

Now....connect the wire from your remote start that is "Negative trigger input hood/trunk" to that wire and all will be fine. Again..I will ask that you NOT confuse this wire with the "negative shutdown" wire.

I can't make it any simpler as if you are not able to do this you really will have troubles if you start messing with diodes...well we see what happened when you did. Why don't you try it the way I am suggesting,? I just don't understand the issue here.

Best of luck, my job should be done here.

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The only trigger wires I have is the negative door trigger and positive door trigger. I do have a hood pin input that acts as a trigger, but that same wire also acts as a remote turnoff, if the hood is opened during remote start.

That is kinda strange..I have never seen a security system that does not give a dedicated wire to protect the trunk/hatch but perhaps it is like a K-Mart unit or something like that. But regardless it is extremely simple to use a pair of diodes to get the trunk protection by tying it into the door wire since they are both negative. If the following diagram does not work or you can't figure it out, then either get a pro to help you or live without it. This is about as basic as it gets....... good luck

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Thanks for the diagram master. I totally understand it. Now my exact setup would be alittle different because I have the door trigger running to my domelight wire. But I would do the same thing as your diagram. My only question is that i had it hooked up the way you had it (running the diode wire from the negative door trigger and ran it to the ground wire that runs from the trunk light. Now I have 2 wires that run off the trunk light; a brown wire and a black (ground wire). Should I just use a DMM and see when there is 12 volt in the brown wire?

Well as long as the wire shows negative when the door is OPEN..and the wire you connect to in the trunk shows a negative when the trunk is open...the diagram will have to work properly for you..do not be concerned with what the wire is called..use a DMM and all will work. The wire for the trunk light you need to tap into will also show 12v positive but ONLY when the trunk is closed. That is ok...just wire the diodes as shown to prevent back feed.

The negative input wire on your system that triggers the alarm is waiting to see a negative...when it does..the alarm cycles..thats all there is to it. When it sees positive or nothing it does nothing.

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