Regular relay question about voltage

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=30669
Printed Date: May 07, 2025 at 2:12 PM

Topic: Regular relay question about voltage

Posted By: bxscig
Subject: Regular relay question about voltage
Date Posted: April 19, 2004 at 11:43 AM

I am trying to install some extra set of fog lights that turn on with the headlights. My car has DRL on the low beams so during the day the voltage supplied to the low beams are less than 12Vs. I was planning on using the low beam harness to trigger the relay to power the fog lights directly from the battery.

I am wondering if the regular relays (with pins 85/96/87/87a/30) will still work when pins 85/86 are powered by something less than 12Vs.

Replies:

Posted By: robbie2883
Date Posted: April 20, 2004 at 6:59 AM

it depends on how low the voltage is.....standard bosch relays usually kick in around 8 volts and drop out around 4

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if its jammed force it - if it breaks in the process it needed to be fixed anyway
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Posted By: bxscig
Date Posted: April 20, 2004 at 9:52 AM

It will be aorund 9 Volts. So what happens between 4 volts and 8 volts? It works in a funky state?

Posted By: robbie2883
Date Posted: April 20, 2004 at 9:45 PM

once the relay gets at least 8 volts it will activate the coil. it will stay activated until the voltage drops below 4 volts.....give or take a volt. that's what it means....no funky stuff! lol

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if its jammed force it - if it breaks in the process it needed to be fixed anyway
posted_image

Posted By: xetmes
Date Posted: April 21, 2004 at 7:16 AM

as robbie2883 says it might work, you may just want to get a lower voltage relay as well.

Posted By: bxscig
Date Posted: April 21, 2004 at 11:01 AM

Thank you, does anyone have a link to a part for the lower voltage ones? The ones I have bought and used are those on Part Express Bosch 20A/30A for like $1.99 each or so.

Posted By: robbie2883
Date Posted: April 21, 2004 at 2:19 PM

check radio shack and look at some of the micro relays

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if its jammed force it - if it breaks in the process it needed to be fixed anyway
posted_image

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