system
 

i have installed several systems but never on a stock headunit. my friend is going to be getting a 12" and a amp. he has a 2005 expedition. i told him id install it. but how exactly would i wire up the rca's or the high power input? and the power on wire? he has a lil stock amp pushing like a 6.5 or something like that. could i tap into that???

Get one of these. That will give you your RCA outputs. For a remote wire you will have to tap into an accessory that powers on with the key. You could get that from the stock head unit. Then run your power wire from the battery and a ground somewhere near the amp.

well here is the deal with that, as you have a couple of options. The first option is using the amplifiers "high to low converter" or "speaker input". This allows you to simple tap into the stock speaker leads to get signal and usually do not require an amplifier control wire. If the amp does not have this option, you can buy a 2 channel "high to low converter" which will convert the speaker lever to RCA level, but you also must run an amplifier turn on wire, which usually requires an "low level signal converter." Companies like soundgate, PIE, and Peripheral make these types of pieces.
You have to be careful though, because if the system is amplified, you have to catch signal after the amplifier, unless you buy a piece that is specifically made for catching signal before the amplifier (which SOUNDGATE and PERIPHERAL so make). You also need to make sure that you signal imputs are hooked up correctly, 100% because if not, then the amplifier will be recieving signal that is "out of phase" which could cause damage to the subwoofer. Ford makes a bunch of diffrent systems for their vehicles, so i cannot tell you off of the top of my head what the wire colors are, so your best bet is to buy the "cheater narness" that you would use if you were putting in an aftermarket stereo and use that as a refrence. Hope this helps!

i was searching around the internet and i found out what i needed to do for the input. the power on is still goin to be a lil tricky but ill just pull of the headunit and look. shouldnt be that much diffrent. i acutually think i can get the remote on from his stock amp and just split the wire.