relay for xm and gps

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=99219
Printed Date: June 23, 2025 at 5:41 PM

Topic: relay for xm and gps

Posted By: audioman2007
Subject: relay for xm and gps
Date Posted: November 21, 2007 at 12:00 PM

Hello. I want to run my gps and my xm radio off a relay. I only want to have power to them when the car is on or in acc. I cant use the cig. outlet for them because my car's cig outlet has constant power. Right now Im running the xm off an interior fuse for something that only has power when car is running. Is there a way I can get power from something to throw the relay in order to get these 2 components to run?

Replies:

Posted By: KPierson
Date Posted: November 21, 2007 at 2:38 PM

You can wire a relay up like this:

Pin 85 - Ignition source (or accessory source, if you have one)
Pin 86 - ground

Pin 30 - Fused 12VDC constant
Pin 87 - 12VDC output

You could most likey hook both devices directly to the ignition (or accessory) wire with no issues at all. Just make sure you fuse both wires appropriately. You really don't need a relay to power them.

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Kevin Pierson

Posted By: hotwaterwizard
Date Posted: November 21, 2007 at 10:33 PM

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John DeRosa (Hotwaterwizard)
Stockton California
When in doubt, try it out !

Posted By: techman93
Date Posted: November 21, 2007 at 10:55 PM

Make sure XM only gets voltage it requires and not 12V+. I think it is more like 5 V+. If you have to, run a voltage regulator to it. Radio Shack item number is 7805. It will cost about $1.60.

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The wire I'm test'n isn't doin' what it's supposed to be doin'... I am so glad I printed that tech sheet, with the wrong info.
Do it right the first time... or I might have to fix it for ya

Posted By: hotwaterwizard
Date Posted: November 22, 2007 at 12:52 PM

The XM runs on 12v and they usually come with an Adaptor if needed 12v to 5v.

You would just hook the adaptor 12v input to the relay 12v output.

Just buy an extra Lighter Socket at the autoparts store, and add it into the 12v output of the relay..

Lets keep it simple so we don't confuse people.

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John DeRosa (Hotwaterwizard)
Stockton California
When in doubt, try it out !

Posted By: audioman2007
Date Posted: November 27, 2007 at 8:26 PM

I just wired it into the relay i have running off my remote turn on wire. It works out perfectly for my xm since you need to have the radio on to listen to music anyways. This way my xm will turn on when my headunit turns on. So I will need to have my headunit turned on in order to get power to my gps. I can still use the gps with my headunit off since i have a 5 hour battery in it. Works for me.