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lkv0315 12-16-2020 09:10 PM

Switched Power
 
Hello all, working on my radio once again, seems to be a never ending story at this point.
I have an LED controller and factory steering wheel controls retainer that are both powered by a 12v in. Turns out the more stuff I add to the switched power and ground of my head unit, the more weird sounds I have to listen to. :rolleyes:
So anyway. Other than off of the radio harness, where should I grab a switched power from (in/behind the dash)? couldn't find much conclusive evidence of what color I should be looking for, as it seems inconsistent. Also, near a ground would be fantastic as well. Thanks in advance!

Caryalon 12-16-2020 09:30 PM

Grounds are brown, red is generally 12v. You'll need to test to see if the 12v is switched or not with a meter or test light.

crystalworks 12-16-2020 09:39 PM

Use your radios acc (switched wire) to trigger a relay. Or trigger it with your radio's remote turn on wire if you have an aftermarket radio. You can grab 12v from the cigarette lighter as your power source for your other devices.

lkv0315 12-16-2020 09:44 PM

Wouldn't a relay just create more electrical noise? And I'm also not sure I understand how that really solves the problem, maybe if you could explain a bit more in depth, I would understand.

Overboost 12-16-2020 10:30 PM

Why not just go to the fusebox. It's right there. :dunno:

Purplefade 12-16-2020 10:39 PM

Quote:

Originally Posted by lkv0315 (Post 1196306)
Wouldn't a relay just create more electrical noise? And I'm also not sure I understand how that really solves the problem, maybe if you could explain a bit more in depth, I would understand.



I think CW is talking about using the remote turn on or amp turn on wire coming from your radio. It is a very low voltage output that would just trigger the relay. Having the 12v “through” source wire coming off the cigarette lighter would provide “conditioned” power from the car and the coil in the relay would act like an insulator against back feed me noise.

He’ll correct me if I’m wrong [emoji106]


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EODguy 12-16-2020 10:41 PM

The cigarette plug in the passenger footwell is a possibility as it is switched power and if not it sleeps when the car does.

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andrewwynn 12-17-2020 01:56 AM

If pulling high power put in a little effort to find the matched ground vs. using a random ground. Classic mistake in house wiring is when people overload a neutral by tapping into a random neutral.

crystalworks 12-17-2020 01:20 PM

Quote:

Originally Posted by Purplefade (Post 1196312)
I think CW is talking about using the remote turn on or amp turn on wire coming from your radio. It is a very low voltage output that would just trigger the relay. Having the 12v “through” source wire coming off the cigarette lighter would provide “conditioned” power from the car and the coil in the relay would act like an insulator against back feed me noise.

He’ll correct me if I’m wrong [emoji106]

Correct. The relay draws a small current, compared to powering other devices. 160mA for a typical 12v 30A relay.

Quote:

Originally Posted by Overboost (Post 1196311)
Why not just go to the fusebox. It's right there. :dunno:

Stop being all logical like that OB. :D Could also grab the 12v feed to the fuse box to be accessory power on the relay instead of the cigarette lighter. Just suggested the lighter is just convenient because it uses larger gauge wire and could handle additional load.

Quote:

Originally Posted by andrewwynn (Post 1196327)
If pulling high power put in a little effort to find the matched ground vs. using a random ground. Classic mistake in house wiring is when people overload a neutral by tapping into a random neutral.

Yes. For sure. Match your power wire size to your ground wire size.

lkv0315 12-20-2020 03:51 PM

Quote:

Originally Posted by crystalworks (Post 1196343)
Correct. The relay draws a small current, compared to powering other devices. 160mA for a typical 12v 30A relay.







Stop being all logical like that OB. :D Could also grab the 12v feed to the fuse box to be accessory power on the relay instead of the cigarette lighter. Just suggested the lighter is just convenient because it uses larger gauge wire and could handle additional load.







Yes. For sure. Match your power wire size to your ground wire size.



So, would I be able to tap the stock amp harness as well? These kinds of sounds were not present with the stock system, so if I switch over to the stock power and ground, it would probably go away right? This is more of a question about my amp than the head unit.

Also, my front passenger seat footwell cigarette lighter port isn’t switched for some reason, it’s constant high. I don’t know why. Thats why I never use it because it just stays on all the time and can drain the battery pretty easily. In my setup, the ground and power are the same size, and they do come from matched pairs. The relay seems a bit too confusing to me, so I think I’ll avoid that route, but thanks for the info regarding that!


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