I bought an s2k and found out it had an infinity 7520a amp in it. I would be more than happy with stock stero but the guy before me added this and wired the car for it. But he took the head unit and threw in the old stock one wich wont work because the speakers are wired to the amp.

Im just wondering what head unit i can get that will work with this. I am assume that the stock head unit wont work unless i go back to stock wiring and i would rather just get another head unit and not mess with that.

i have a couple pics.

 

Any after market head with pre-amp (RCA) outputs will work. A lot of owners pick up an Alpine head unit. Then they purchase a "pulg and play" wiring harness and Dash Control Interface (DCI - makes the volume controls to the left of the steering wheel function with a aftermarker head unit) from Modifry (www.modifry.com). Both the Harness and DCI only work with Apline head units.

 

Does all of that look good? This is how it was when i bought it. I cant figure out how to get and aftermarket head unit wired up to it. Do i just need the wiring harness?

 

those blue wires labeled "KnuKonceptz" are the RCAs - they plug into
preamp outputs on aftermarket headunits to get the signal to the amp.
Alternatively, you can buy a line output converter (LOC) which takes
speaker wires from the OEM headunit and converts to low-level RCA.
it looks like the speaker wires from the amp terminate by the headunit,
so I suspect the previous owner connected them to the car's harness
rather than running them to the speakers in the doors.
it would be very easy to hook up an aftermarket headunit, and possible to
hook up the amp to the OEM headunit, though to do it without cutting the
car's harness you'd need to buy a couple adapter harnesses and splice them
together (plus the LOCs)

 

Ok as long as its pretty straight forward circut city will do it for free they told me if i buy a head unit and harness they install for free. If they werent doing it for free i would do it myself .

 

be aware that if you want your dash controls to work with an
aftermarket headunit, you need a dash control interface (DCI)
which Circuit City probably doesn't sell.

 

Def get the DCI, it is great.

 

Actually the DCI can be made to work with many different brand headunits. It has dip switches to change the settings to work with the other HU's.

 

You can check Modifys website for compatable brands.

 

I am interested to know why the speaker wires are unhooked behind the HU like that. If he was running the stock speaker wires, they would be in the harness. If he is running aftermarket wires from the amp to the speakers, they still would not terminate behind the HU like that... they would terminate at the amp and in the doors... I would verify where those wires are going and what they are plugged into.

I have the same amp pushing my rear channel S-pods. Decent budget amp.

As far as "getting it working", you will need to verify why those speaker wires are open like they are behind the HU. If you plug in a HU, and wire up the RCA's perfectly, it will not work if the speaker wires from the amp do not meet the speakers (but instead are open like they appear to be behind the HU).

You have 2 problems that I can see:

1) The amp is not getting the RCA/amp remote signal. These need to be hooked up. You will need a Line Output Converter if you plan on keeping the OEM HU. You will need to CUT the speaker wires in the wiring harness, and run them into the LOC converter. The RCA's will then run from the converter to the amp. Or, you could just by any aftermarket HU with RCA pre-outs, and just run the RCA's from the HU to the amp (no cutting of the stock harness and no LOC unit needed).

2) The speaker wires behind the HU. Find out where those go and what they are "supposed" to do. The could be either of the following:
a) Replaced OEM speaker wiring that was never re-pin'ed into the OEM harness (in this case, they will run from the HU area to the doors).
b) Added channels for rear speakers. In this case, they will run behind the seats.
c) Speaker level outputs from the amp that were never properly run through the doors (not sure why this would have happened. In this case, they will run from the HU area to the amp.

I doubt these wires had anything to do with an LOC from the previous owner, as you said he had an aftermarket HU that worked normally...

Happy hunting!

John