Adding a door 3rd door pin

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=73499
Printed Date: May 17, 2025 at 8:05 AM

Topic: Adding a door 3rd door pin

Posted By: majistir
Subject: Adding a door 3rd door pin
Date Posted: February 25, 2006 at 8:56 PM

Hi, I have a 94 Civic hatch. When the alarm was installed the doors work fine but the backglass doesnt have a door pin like the front two. If I were to add one in the back and cut into the wires on the passenger side would the alarm sound if the backglass was open and the passenger side was closed??

A relay seems like it would fix this problem but I dont have any experience in this kind of stuff. From the diagrams I have seen it looks like the relay would only be able to power one or the other... so if someone out there could help me, you could help save a car. :) Thanks.

Replies:

Posted By: majistir
Date Posted: February 26, 2006 at 12:51 AM

anybody? its been really bugging me.

Posted By: hotwaterwizard
Date Posted: March 01, 2006 at 12:06 AM

Just put the other switch in series with the existing switch.

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John DeRosa (Hotwaterwizard)
Stockton California
When in doubt, try it out !

Posted By: majistir
Date Posted: March 01, 2006 at 1:54 AM

I didnt think that would work... but the switches arnt open when the doors are closed so when one is opened.... lol Thanks alot man!

But what if the circuit is live when the doors are closed? Guess I'll go pop one out and see if the dome light comes on if the 2 wires are connected or separated.

Posted By: hotwaterwizard
Date Posted: March 01, 2006 at 9:03 AM

Just make sure the switch is the same as the rest. Norm open norm closed. You know what to do. If you can not find one the same you can use a relay.

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John DeRosa (Hotwaterwizard)
Stockton California
When in doubt, try it out !

Posted By: schmoo
Date Posted: March 01, 2006 at 2:38 PM

civic should have negative door switches. Meaning in closes the switch to ground when the door is opened. Put the switches in parrallel to each other ( before the door side). That should work fine. I did a install a long time back in a 93 and there was a dsh light to signal open trunk, i used that and tied into the hood switch wire through a relay to change polarity if I remeber right.

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a true canadian eh!