trunk release without button

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=68472
Printed Date: May 09, 2025 at 7:17 PM

Topic: trunk release without button

Posted By: bigt_45
Subject: trunk release without button
Date Posted: December 15, 2005 at 8:46 PM

Is there any way to trigger a negative signal to open a trunk if the only buttons on a transmitter are the lock and unlock? Can you set up a relay or anything to trigger one negative pulse from two or three positive pulses?

Replies:

Posted By: desh187
Date Posted: December 15, 2005 at 9:07 PM

What alarm system is this?

Posted By: bigt_45
Date Posted: December 15, 2005 at 9:24 PM

Its not an alarm, just keyless entry and remote start (Code Alarm 510).

Posted By: mo12v
Date Posted: December 15, 2005 at 9:56 PM

Doesn't the 510 have a 3rd Channel Output??

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MO

Don't Learn from Others Mistakes
You Might Be the One That Knows.

Posted By: dualsport
Date Posted: December 16, 2005 at 2:55 AM

Certainly use the 3rd channel control if it has it, but just for the heck of it, you could try this-

If it gets two consecutive pulses within a second or so, it should put out a momentary pulse to do whatever you want-
If only one pulse comes in, it should ignore it and not put out anything. Might need to tweak the values of the caps and resistors to change the timing to suit.
The CD4013BCN chip is about 50 cents or so-

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Posted By: dualsport
Date Posted: December 16, 2005 at 11:40 AM

Oops, that definitely won't work with the reset pin tied to 12V- should have been connected to ground-
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Posted By: Mike M2
Date Posted: December 16, 2005 at 6:48 PM

If the keyless has dome light survailance, you can use a relay to flip the unlock wire with that output. First push of unlock will do unlock and flip relay, second push will pop trunk....

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Mike M2
Tech Manager
CS Dealer Services

Posted By: dualsport
Date Posted: December 16, 2005 at 7:09 PM

That's a good idea- could use any output that's active when in either an unlocked or locked condition as a control.

Then if the doors are already unlocked, pressing the unlock will pop the trunk. Then there's no timing to be concerned with.

Just have to see if he's got any type of output like that, like a ground while armed kind of signal.