spacer spacer spacer spacer

Volt Meter LED Warning How To?

Post ReplyPost New Topic
< Prev Topic Next Topic >
Member - Posts: 9
Member spacespace
Joined: October 09, 2020
Posted: October 09, 2020 at 9:54 AM / IP Logged Link to Post Post Reply Quote jonas2
Hello! New here, first post, probably wrong place but this looked like inactive area of the forum, mods., please feel free to move as appropriate. But here it is...
Automobile application, wiring in a new voltmeter - VDO Viewline Onyx, to replace my old VDO cookpit. The new one has an LED warning bulb, but it is just +12V and ground - nothing in the gauge tells the LED to come on in the case of low voltage, so a "sensor" of sorts needs to be wired into the LED + and -.
My initial thought was to use a 5 pin relay in which the LED +12 is on the NC contact wired to the ignition switch, so when the key is "on", that circuit is energized and the LED is lit. Once the car is running and generating enough voltage, I wanted that wire to activate the relay, which would disable the NC and kill the LED light Then, if the car started to have a failure in the charging circuit, the relay would de-energize and the LED would come back on. The trick is what component to add to the 86 terminal of the relay that would allow current to flow say when the voltage was greater than 12.5 - 13V? I thought maybe a diode or transistor of some sort, but I really don't know enough about components to make this work.
Unfortunately, factory offers NOTHING for this, and their response is "well, most people just don't use it...." (O.k., then WHY did you put it in there?) -I'd like to use it... My approach may be totally wrong here, so just looking for advice on a new approach, or how to make mine work if it seems reasonable. Thanks much!
Gold - Posts: 593
Gold spaceThis member consistently provides reliable informationspace
Joined: July 18, 2008
Location: Washington, United States
Posted: October 14, 2020 at 11:55 AM / IP Logged Link to Post Post Reply Quote tonanzith
maybe use this?
low voltage alarm
Gary Sather
Silver - Posts: 1,338
Silver spacespace
Joined: August 08, 2012
Posted: October 18, 2020 at 4:12 AM / IP Logged Link to Post Post Reply Quote lurch228
Warning indicator is integrated into the gauge! It has 4-wires positive and ground for sensing and positive and ground for backlit (illumination).
Volt Meter LED Warning How To? -- posted image.

If you wish to post a reply to this topic, you must first login.
If you are not already registered, you must first register.

  Printable version Printable version Post ReplyPost New Topic
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot delete your posts in this forum
You cannot edit your posts in this forum
You cannot create polls in this forum
You cannot vote in polls in this forum

Follow Follow on Facebook
Monday, May 20, 2024 • Copyright © 1999-2024, All Rights Reserved Privacy Policy & Use of Cookies
Disclaimer: *All information on this site ( ) is provided "as is" without any warranty of any kind, either expressed or implied, including but not limited to fitness for a particular use. Any user assumes the entire risk as to the accuracy and use of this information. Please verify all wire colors and diagrams before applying any information.

Secured by Sectigo spacer spacer spacer
Top spacer spacer