trunk popper: want circuit off when car is running
Printed From: the12volt.com
Forum Name: Relays
Forum Discription: Relay Diagrams, SPDT Relays, SPST Relays, DPDT Relays, Latching Relays, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=4333
Printed Date: July 19, 2025 at 5:21 PM
Topic: trunk popper: want circuit off when car is running
Posted By: ohmysac
Subject: trunk popper: want circuit off when car is running
Date Posted: October 10, 2002 at 10:43 AM
i'm wiring a trunk popper using this wiring(not sure if this could work or not: 
but i'd like to make it so the trunk wont pop if the car is running...i dont want my trunk flying open as i'm going down the road! :) how would i go about doing that? thanks!!!
Replies:
Posted By: the12volt
Date Posted: October 10, 2002 at 11:21 AM
Typically your second channel will not work when the ignition lead is showing 12V+, but you can use an additional relay to open the second channel output to the relay when there is 12V+ showing on the ignition lead and wire the two relays as follows if your second channel output from the alarm is a negative output.. Relay 1 (used to pop trunk)
85 to 87a of second relay
86 to constant 12V+
30 to constant 12V+
87 to positive lead of solenoid
87a not used Relay 2 (used to inhibit channel 2 output)
87a to 85 of first relay
30 to second channel negative output from alarm
86 to ground
85 to ignition lead
87 not used If the alarm's second channel output is a positive output, connect terminal 86 of the first relay to ground instead of 12V+. the12volt
Posted By: ohmysac
Date Posted: October 10, 2002 at 3:52 PM
my 2nd channel output does operate when the ignition is on....and it is a positive output of 0.6v ...will this be a problem?
Posted By: the12volt
Date Posted: October 10, 2002 at 4:18 PM
No, not at all, connect it as follows: Relay 1 (used to pop trunk)
85 to 87a of second relay
86 to ground
87 to positive lead of solenoid
87a not used Relay 2 (used to inhibit channel 2 output)
87a to 85 of first relay
30 to second channel positive output from alarm
86 to ground
85 to ignition lead
87 not used Anytime the ignition is on, the coil of the second relay is energized and opens the connection of the alarm's positive output to the coil of the first relay preventing the trunk from opening via your remote. the12volt
Posted By: ohmysac
Date Posted: October 10, 2002 at 4:33 PM
what type of relay do you recommend? i know spdt but what brand and specs? i'm just learning about all this electrical stuff...my concert was that the 2nd channel output wouldnt be strong enough to energize the coil
Posted By: go2pac
Date Posted: October 10, 2002 at 5:39 PM
You sure its a positive 0.6 volts? If it is, its not enough to energize a relay. I think you are measuring it incorrectly. One test lead should go to a constant 12volt source and the other lead to the 2nd channel wire. When activated, you should measure 12volts. That would be a negative output.
-------------
Karl
Pacific Accessory Corporation
Mobile Audio Interfacing Equipment
Connecting You to Your Music Since 1976
Posted By: ohmysac
Date Posted: October 10, 2002 at 5:48 PM
ahh...thank you for showing me the way! i'll go try this...i'll keep you updated...
Posted By: the12volt
Date Posted: October 10, 2002 at 5:50 PM
Glad you spotted that Karl, my bad. That won't be enough to energize the coil of a relay. What alarm are you using ohmy? If you do have a negative output, connect the relays as I described in my first reply.
Posted By: ohmysac
Date Posted: October 10, 2002 at 6:05 PM
i dont know if i do or not...i have no wiring diagram... its an autopage rf-1055KE ---> https://www.autopageusa.com/autopageusarf1055ke.htm
Posted By: go2pac
Date Posted: October 10, 2002 at 10:50 PM
Though the12volt first post would work, this one here would not energize any relays until you need to pop the trunk. When the ignition is off the ignition wire will supply ground for the second relay. 
------------- Karl
Pacific Accessory Corporation
Mobile Audio Interfacing Equipment
Connecting You to Your Music Since 1976
Posted By: ohmysac
Date Posted: October 11, 2002 at 10:38 AM
i dont know if its just me but that looks like the popper would work only if the ignition is ON
Posted By: the12volt
Date Posted: October 11, 2002 at 11:47 AM
The ignition lead will show ground in the off position and 12V+ in the on position. Follow the signal path from the first relay through the second. When ground is applied to terminal 85 of the first relay, 12V+ is sent to terminals 86 and 87 of the second relay. The coil of the second relay will then energize if the ignition is off as ground will be present on the ignition lead.
Posted By: ohmysac
Date Posted: October 12, 2002 at 10:45 AM
i just tried out this configuration...the ignition lead does not act as a ground in the off position...so i guess this configuration will not work...the12volt's first post worked perfectly...so i guess i'm going to stick with that...
Posted By: djfearny2
Date Posted: October 13, 2002 at 10:40 AM
why are your worried about the trunk popping when your car is running etc. it will only pop if you want it to meaning if you press the button that negative from the alarm or possitive whatever need that signal from alarm to even think of working and the only way it will get that signal is if you give it. and press the button no need for two relays. stop worrying. ------------- 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: ohmysac
Date Posted: October 13, 2002 at 10:44 AM
i like things being complicated... :)
Posted By: djfearny2
Date Posted: October 13, 2002 at 6:45 PM
there is no need for them to be///... ------------- 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: ohmysac
Date Posted: October 14, 2002 at 11:34 AM
no the real reason why i'd like it this way is because i have kids who like to press buttons...just a precaution and the fact that i'm putting in higher powered gas struts so the trunk opens automagically
Posted By: omega
Date Posted: October 21, 2002 at 1:10 AM
Just wire the first relay like go2pac showed but change the second relay so that you have one end of the coil grounded and the other end of the coil connected to ignition. Then connect the end of the wire that will trigger the trunk (coming from the first relay) to Pin30 and then connect the end going to the trunk solenoid to Pin87a and you're done. When the relay is NOT energised, channel2 will be continuous with the trunk solenoid. When it is energised (i.e. the ignition is on) the relay will break continuity and you won't be able to open the trunk with the remote. That simple! (Actually, you could also use the 2nd posting by the12volt, as this would also work!)
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