relay question-momentary to constant

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=43350
Printed Date: July 15, 2025 at 3:27 AM

Topic: relay question-momentary to constant

Posted By: spear
Subject: relay question-momentary to constant
Date Posted: November 19, 2004 at 3:54 PM

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I have been working (unsuccessfully) with the above setup, using the unlock pulse from my remote to turn on the courtesy and backup lights in my Tacoma. I added a third relay to break contact between 85 and 87 using the door trigger to open the 87a-30 contacts. That way the lights come on with the unlock pulse and then go off when the door is opened (except courtesy lights stay on until door is shut). Here are my questions.

#1 I had to add a fourth relay to convert the positive output to negative output.

Is there a way to do 'momentary to constant negative output' with fewer relays?

Also, when I add the 4th relay, I get problems with the latching not working. I need diodes added I'm sure but don't know where.

Could someone illustrate where the diodes go and maybe set up a diagram as I've tried to create? THANK YOU!!! :)

Replies:

Posted By: daniel2002p
Date Posted: November 19, 2004 at 11:01 PM

what year tacoma?

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2005 Toyota Corolla S
1.8L VVT-i I-4
Always double check your wires with a DMM!!!
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Posted By: dragonrage
Date Posted: November 20, 2004 at 12:39 AM

Make the unlock pulse trigger a latch IC with the output going to a transistor which goes to a relay to the light switch(es). Connect another relay that is controlled by the door signal so that when the door is opened, the latch gets reset to off.

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2009 Pontiac G8 in planning stage
HU: ?
Speakers: ?
Amps: ?

Posted By: dragonrage
Date Posted: November 20, 2004 at 12:41 AM

Okay, my last post did go through, even though the board said it didn't 'cause I was spamming (BS)

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2009 Pontiac G8 in planning stage
HU: ?
Speakers: ?
Amps: ?

Posted By: TimothyCox
Date Posted: November 21, 2004 at 12:02 AM

I built a circuit a while back to do this job, Here is my best rendering.

This should cost about 15 bucks to make and uses none or 1 relay, depending on the lights being driven. Hope this helps, good luck. Tim

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