# How would I add a relay to turn on a new device when the car is on?

**URL:** <https://forums.speedlife.net/t/how-would-i-add-a-relay-to-turn-on-a-new-device-when-the-car-is-on/27716>\
**Category:** NYSpeed Automotive\
**Created:** [April 16, 2007, 11:57am UTC](https://forums.speedlife.net/t/how-would-i-add-a-relay-to-turn-on-a-new-device-when-the-car-is-on/27716 "2007-04-16T11:57:32Z")\
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**Showing post:** 11

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**Author:** ![greg23](https://avatars.discourse-cdn.com/v4/letter/g/e9bcb4/32.png) [@greg23](https://forums.speedlife.net/u/greg23)\
**Post date:** [April 16, 2007, 3:20pm UTC](https://forums.speedlife.net/t/how-would-i-add-a-relay-to-turn-on-a-new-device-when-the-car-is-on/27716/11 "2007-04-16T15:20:39Z")

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Dont throw a relay in there, theres no point.

Like stated above, use the ignition wire or accessory wire at the steering column, going to the key cylinder.

Black/Red = Ignition wire  
Blue = Accessory wire

Both will switch when the key is on and off. Make sure you use a inline fuse. 10 amp would be more than enough.

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