Print Page | Close Window

using relays for door pins

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=46201
Printed Date: May 10, 2025 at 6:28 PM


Topic: using relays for door pins

Posted By: flyboy172152
Subject: using relays for door pins
Date Posted: December 28, 2004 at 11:21 AM

 how can i make + door pin output into a - for a car starter?  i have tried the ways sugested on this site, but the problem is if i hook the +12 coming from the door pin to 85 on the relay and ground 86 it bypasses the pin swithch and then the dome light will come on and the car thinks the door is open.   it is a 2000 ford mustang whitch has +12 when the door is closed and nothing when it opens, the remote starter needs to see -12 volts? if anyone has any idea let me know thanks.



Replies:

Posted By: hotwaterwizard
Date Posted: December 30, 2004 at 12:27 AM

You want the Car to start when you open the door?

There are Issues to address.

The starter will keep going as long as the door is opened.

The starter will grind when you open the door if the car is running.

Or maybe I don't understand what you want.



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




Posted By: flyboy172152
Date Posted: December 30, 2004 at 11:26 AM
  the remote car starter needs to see a -12volts in order to start the car remotly.  so it needs to know if the door is open or close. on my car 2000 mustang it has a +12volts when the door is closed, so i was wondering how can i reverse the polarity of this wire? but it can not be hooked to a ground because it then bypass the door switch and tells the car that the door is open.  the other thing is, i have treid this with a yellow and black wire, it shows 12 volts when closed and 0 volts when open is this the right wire for the door pin switch? on mustangs the swithch is part of the lock itself.




Posted By: geepherder
Date Posted: December 31, 2004 at 9:35 PM

Yes, that's the right wire.  Here's what you need to do.  Connect that wire to one side of the coil (85 or 86).  Connect the other side to a fused 12 volt constant.  Now connect terminal 30 to ground, and 87a to your remote start. 

The remote start will now see ground until a door is opened, and the NC contacts are broken.



-------------
My ex once told me I have a perfect face for radio.




Posted By: flyboy172152
Date Posted: January 01, 2005 at 1:25 AM
thanks a bunch  i will have to try that and see if it works





Print Page | Close Window