relay, lighted switch?

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=83441
Printed Date: May 10, 2025 at 4:19 AM

Topic: relay, lighted switch?

Posted By: joenintiesc
Subject: relay, lighted switch?
Date Posted: September 27, 2006 at 10:21 PM

This is a great site but I couldn't find an answer to this hopefully simple question. And advice would be greatly appreciated!

I've wired a fan in my car according to this schematic here:

https://www.sccoa.com/forums/attachment.php?attachmentid=6081

But then I realized that I have a lighted, three prong rocker switch, wheras the diagram is using an unlit switch. Is there a simple way I can add another wire to the switch to get the switch to light when the fan is powered on? Do I need to tap into an ignition power wire?

Thanks for any help!

Replies:

Posted By: bsd1
Date Posted: September 27, 2006 at 11:43 PM

Move the switch to the positive side (85) and fuse the wire going to 85, 3A probably okay. Yes, get that 12V from ignition.

Posted By: bsd1
Date Posted: September 27, 2006 at 11:46 PM

You can use DPDT switch and run a 12V to it to get it light up when powered on, but it's redundant when you can simply move the switch to the positive side.

Posted By: joenintiesc
Date Posted: September 28, 2006 at 10:31 AM

Thanks for the quick reply! Is there an easy way to tell if a switch is DPDT? I bought a custom made switch panel with the switches already installed, and the switch itself doesn't have DPDT written on it... I'm just thinking that would be the quicker fix as opposed to re-running the wiring.

Posted By: bryantobando
Date Posted: September 28, 2006 at 10:45 AM

A Double pole, double throw switch has 6 tabs

Posted By: joenintiesc
Date Posted: September 28, 2006 at 11:59 AM

Thanks! No just to make sure I have it right, can this be confirmed?:

On relay:

86 gets grounded (shared ground with fan)

85 goes to rocker switch (prong#1?), then from rocker switch (prong#2?) connects to "switched" 12V power w/ fuse

87 goes to fan

30 goes to battery (starter relay) with 10 amp fuse

remaining prong on rocker switch goes to ground.

Is that about right, or not? Thanks again for your help!

Posted By: joenintiesc
Date Posted: September 28, 2006 at 2:31 PM

Ok, I think I got it:

| - Pin 30 - Main power in
Pin 85 - Ground - | | - Pin 86 - connect to ignition
Pin 87a - Not used __
Pin 87 - Connect to fan __

Thanks again Bryan and bsd!