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Using factory wiring and fuses to power amps

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=142996
Printed Date: March 28, 2024 at 4:34 AM


Topic: Using factory wiring and fuses to power amps

Posted By: mauriceh780
Subject: Using factory wiring and fuses to power amps
Date Posted: May 23, 2017 at 6:45 PM

I am doing a new install in a 2015 Hyundai Accent.

Pioneer head with no speakers being driven.

Kenwood amp KAC M1804 (400W) for the door speakers.
Powerbass amp ACA-480.4 ( 4 ohm bridged mono 2 x 240W) for the rear sub.

I look at the fuse block in the dash and I see a circuit: "Stereo 20A" and it comes with a factory installed 20A fuse.
The Kenwood has a 15A fuse in it.

I see that most car installers like to ruin a big fat 8 gauge wire to the battery ( or even bigger) but I find that a bit odd.
The Amp has input wires that are 16 gauge. It has a 15A fuse in it from the factory.

Can anyone explain to me a reason I should not use the factory 20A stereo circuit for powering the Kenwood amp and the Pioneer head unit?

Thanks!



Replies:

Posted By: pasoundworks
Date Posted: May 24, 2017 at 6:11 PM
The Kenwood amp will run fine off the factory deck wiring. Are you powering the powerbass amp separately?

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P.A Soundworks
Prince Albert,Sk,Canada




Posted By: mauriceh780
Date Posted: May 24, 2017 at 7:51 PM
Really? The Kenwood has 16 gauge wires.
The factory deck wires are NOT the one on the fuse panel that is labeled "Stereo" with the 20 amp fuse.
The Powerbass will get a separate of 8 gauge power cable. It is about 15' of cable from the battery.




Posted By: pasoundworks
Date Posted: May 25, 2017 at 6:28 PM
Yep i just did that same thing in my buddy's truck

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P.A Soundworks
Prince Albert,Sk,Canada




Posted By: mauriceh780
Date Posted: May 25, 2017 at 10:53 PM
It just seems so much cleaner than butchering the factory wiring, drilling hole in the firewall,
when there are factory circuits there ready to use.

Thanks buddy, appreciate the time and thought you shared with me.





Posted By: series vii
Date Posted: June 06, 2017 at 12:48 PM
Most manufacturers today are reducing vehicle weight however and where ever possible. Wiring is one such place this is happening. It seems like they are willing to accept voltage drops to accomplish this, meaning minimum wiring gauge to accomplish stock only equipment or accessories. That being said, voltage issues are a possibility depending on distance to the load. It is possible that 20amp fuse hits 18awg wire and is 10 feet long. Not a big deal for a deck but an amp also? Say for some reason you do have a short or the insulation melts inside a factory loom, what else will be affected and or will the warranty be invalid? Pioneer had some high power decks back in the day that specified a 14Awg run directly to the battery for this reason. I run my own wire and fuses and stay away from the factory wiring when ever possible for power. Trouble shooting is easier and also a bit of deniability if an electrical issue surfaces. Dealers will point to anything aftermarket as the problem source. Being a 2015, I would spend the time and $30 bucks in parts to isolate. My 2 cents.




Posted By: mauriceh780
Date Posted: June 08, 2017 at 2:11 PM
Thanks for that, "series vii"
Makes some sense.
20 amp at 12V only requires a 14 gauge wire.
And just because there is a 20A fuse there does not mean I expect to be drawing that much juice!

What ended up clinching the deal for me is that to get at the back of the fuse panel to try and trace where those wires come out of that fuse is a bear.
There are 12 BIG harness connectors attached to the fuse panel, and getting at all of them is really tough.

I tried a couple of Hyundai dealerships to see if they could help me by looking up the wiring diagrams, but they were useless.
In the end I threw in the towel.

Ran a 4 gauge standard stereo wiring kit cable and cut a small hole in the plastic bootie at the battery terminal.
Not as pretty as I would have liked, but serviceable.






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