Fuses and Head Units

[Edward_Stryfe]

So I am shopping around to figure out what to start myself off with, but I'm going to be doing this on my 1st car. I've got most of everything mapped out in regards to the amp and subwoofer I want to add. The amp I'm going to get for my sub will be

Rockford Fosgate Prime Class D 1-Channel Amplifier

http://a.co/0olAcOa

And the sub would be

Skar Audio EV-10 S2 10" Single 2Ohm 400watt Shallow Mount Car Subwoofer

http://a.co/5vZrraP

Since I'm on a budget I'm not going to immediately replace the factory speakers and amplify them yet. I'm gonna make the jump to add a sub first. But I'm not sure what my limits are on a battery. I'm also unsure about what's in store for me with the head unit, because it came built in with this service called onstar that is involved with the sound system and hooked up to rear view mirror. I'd like to for now just keep the factory head unit and make some sort of, "by any means necessary" connection to the sub. But that service has me questioning whether or not I can do that. I also haven't seen any guidelines to what a good range of fuse would be to use on varying setups.

So what I need help with is finding out if there's any extra business that has to be dealt with because of an onstar system, if you can hook a sub up to a factory head unit, and what a safe range would be for me to get a fuse to connect my battery and amp(s). I know that onstar has to do with security to a degree and when you have the service it does various things, but would it be especially difficult to do things with this head unit or even to remove it?

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[adulbrich 5,000+ posts]

Use an LOC (line output converter) to tap into your factory head unit.

I don't know if that amp takes 4 or 8 gauge. For 4 gauge, use 100 to 150 amp fuse. For 8 gauge, use a 50 or 75 amp fuse. Depends on if it's actual size, and if the wire is CCA or OFC. OFC is better all around, except it's more expensive. I don't like CCA, but I think you could get away with 4 gauge CCA on this with a 75 or 100 amp fuse near the front battery

 

[Edward_Stryfe]

Thanks for all this, I've seen the converters around, is there really any better than the other?

Do I need a fuse for the negative line as well? or is that line fine with a direct connection?

 

[adulbrich 5,000+ posts]

Either of these would probably be fine:

Car Audio Adjustable High Low Line Output Converter LOC Gain Control LC012 | eBay

SCOSHE LOC80 2-CHANNEL ADJUSTABLE CAR AUDIO LINE OUTPUT CONVERTER | eBay

I don't be believe there's a big difference between all the LOC's on the market. They're relatively simple devices. Only real difference would be component quality. You could pay a little more if you want, but from the sound of it, you're piecing together a first-time budget system. It's up to you. If you have extra money left in the budget, sure, splurge on a higher quality LOC.

Negative does not need a fuse. You're wiring it directly to the metal ground of your vehicle, so it does not matter if it touches ground anywhere after your amp, even if the wire is cut. You just don't want it to arc off on anything positive.