relay wiring

Home / the12volt's Install Bay / Relays / relay wiring (

Topic Closed)

Welcome Guest :)

Members

< Prev Topic Next Topic >

fronedaddy

Member - Posts: 4

Joined: February 25, 2006

Location: United States

Posted: January 19, 2009 at 9:40 AM / IP Logged

Hello, I have a switch that I am using on my truck. The switch is being used to complete a 5 volt circuit. I want to add an L.E.D. light that mounts in the dash to turn on when the switch is on. Is it possible to use the 5 volt wire to the relay to turn on the 12 volt L.E.D.? If so, could someone please explain how to wire it and a diagram would be great. Thanks!

i am an idiot

Platinum - Posts: 13,672

This member consistently provides reliable information

Joined: September 21, 2006

Location: Louisiana, United States

Posted: January 19, 2009 at 10:15 AM / IP Logged

If it will light up a 12 volt LED it will be very dim. Why not get a standard LED and wire a 100 ohm resistor in series with the LED.

fronedaddy

Member - Posts: 4

Joined: February 25, 2006

Location: United States

Posted: January 19, 2009 at 10:36 AM / IP Logged

Because there is a certain LED that I am planning on using. That's why I'm asking, isn't there a way to run a 12 volt wire into the relay so that when the relay senses the 5 volts from the switch it connects power from the 12 volt line to the light, and giving the light the full 12 volts? The only thing the 5 volt line would be used for was to signal the relay to close the circuit from 12 volt constant to the light.

i am an idiot

Platinum - Posts: 13,672

Joined: September 21, 2006

Location: Louisiana, United States

Posted: January 19, 2009 at 1:12 PM / IP Logged

Radio Shack sells a relay that has a 5 volt coil.

KPierson

Platinum - Posts: 3,527

Joined: April 14, 2005

Location: Ohio, United States

Posted: January 19, 2009 at 3:03 PM / IP Logged

You could do it with a standard 12vdc automotive relay:

Rewire your current switch so that one side is grounded and the other side goes to pin 85 of a Bosch style relay. Wire Pin 86 to constant (or ignition) 12vdc

Use the contacts (Pin 30 = Com, Pin 87A = NC, Pin 87 = NO) to complete your 5vdc circuit.

You can then connect the (-) side of your LED to Pin 85 of the Bosch relay. Wire the + side of the LED to 12vdc constant or ignition.

You will also need a diode across the coil of the relay - connect the striped side of the diode to Pin 86 and connect the "unstriped" side to Pin 85. This diode will protect the discreet LED from being damaged from the collapsing of the magnetic field in the relay coil when power is removed.

Kevin Pierson

fronedaddy

Member - Posts: 4

Joined: February 25, 2006

Location: United States

Posted: January 20, 2009 at 12:13 PM / IP Logged

Thanks for the replies, I got this suggestion from someone else...

I'm sure you won't understand the wording but the wire going to the air pressure sensor is the 5 volt circuit. The resistor is to prevent a CEL from being thrown.

relay wiring -- posted image.

Sorry, you can NOT post a reply.
This topic is closed.

Printable version

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

Search the12volt.com

Follow the12volt.com

Disclaimer: *All information on this site ( the12volt.com ) 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.

relay wiring

Sorry, you can NOT post a reply.This topic is closed.

Sorry, you can NOT post a reply.
This topic is closed.