Need help, how to wire amp and subs to stock head unit??

[Millers1504x4]

A buddy of mine recently bought a 2002 Ford Expedition Eddie Bauer edition. Anyway I was trying to help him wire an amp an subs to it. However I've never had a problem where someone wants to keep the stock head unit and do it so I'm lost. He wishes to keep the stock unit since it is a 6 disc cd changer. The things I'm lost on is pretty much all the wiring except the ground and the power. The only problem I have is I've no clue where to ground it. I guess what I'm asking is has anyone kept the stock ehad unit and added a sub and amp to it an how was it done?

 

[tonydiv]

Since the factory head unit doesn't have pre amp outputs, you need to pick up some 'black boxes' to bring the speaker level outputs down to amp level inputs. These are available at Best Buy or on ebay. Keep in mind that they will produce a tiny bit of hiss.

So here's your basic setup. Speaker wires from head unit go to black boxes. Black boxes go to the power amp. New speaker wires go from amp to the speakers. A crossover goes from the main amp to the sub amp. (unless the sub handles that duty)

If you're just adding a sub, then you can tap the black boxes off the existing speaker wires and go to the sub amp.

I like to run my amp power wires (both pos and neg) directly to the battery. This way, you don't have to worry about 'iffy' grounds to the body.

 

[Millers1504x4]

Thanks for the info. So what exactly are these black boxes? I've always heard that you want the ground as short a distance as you can get it? If not then I'll suggest he pick up an extension kit and run the ground to the battery also.

 

[Millers1504x4]

is the black box anything like a FAI-3A scosche pre-aftermarket thing? It's like a blue box looking thing. Totally lost on what it does but I have it anyway.

 

[jwgavin]

so i have one of these i'm wondering how i set it up and what wires through my 6 disc i need to go through and if theres a diagram that can help me

 

[Millers1504x4]

so i have one of these i'm wondering how i set it up and what wires through my 6 disc i need to go through and if theres a diagram that can help me

And this would be the buddy I was talking about just to clear things up

 

[GAINMOB]

I had my system hooked up to my stock before switching out units...as soon as I can get on my computer I can give you picks of how I ran my signal converter...I hooked it up on the rear subwoofer...

Sent from my BlackBerry 9810 using Tapatalk

 

[jwgavin]

That would be great but would it be the same setup in mine as it is in yours?

 

[GAINMOB]

 

[GAINMOB]

i used the +/- input from the sub and matched it with the left/right for the speaker inputs...plug rca from amp to it...BASS...the rest of the install for the amp is the same...ground anywhere on the truck...best to be as short as possible but no probs if it isnt...run power from amp to battery with 12 or less to put in the fuse...find your remote turn on either on the stereo or fuse for the ACC/ON for the ignition...speaker wires and youre done