99 Lexus GS400, system, wiring

I need some help swapping out the Nakamichi HU in a 99 Lexus GS400 with a Pioneer AVIC-D1.  I want to keep the swap as simple as possible.

I looked at the wiring diagram for replacing the HU and am still in the dark on how to do this myself. 

1. Is this the correct diagram http://lexusmodz.netfirms.com/GS_DIY/stereo/  ?

2. Is there an even more simplified version of that wiring diagram?  I want to replace my NAK HU with a Navigation system (Pioneer AVIC-D1) and was wondering what (if any) I need to buy in terms of a wiring harness or (anything else) such to connect the nav to the existing amp in the trunk.

In short I need some help making this DIY task as simple as possible so that even a simpleton like myself can do this at home.

I know that I have to hookup the speed sensor to the appropriate wire in the car and I noticed another DIY on the website linked above http://lexusmodz.netfirms.com that identifies that cable behind the instrument cluster - so I think I can get to that one.

Found this page here that has a description of the wires, but this is still foreign to me!  :(

https://www.the12volt.com/installbay/detail.asp?info=alarm&year=1999&make=Lexus&model=GS300/400&ID=18201&type=Stereo

Can anyone make this simpler for me please?  I can't afford to pay a professional to do the wiring, so need to figure this out myself.  I will be eternally grateful to anyone who can help me with some guidance and tips.  If you are in town, I will even give you a free meal to install it for me at my house in your free time.  :D

Better yet, if I am brave enough I could swap out the factory amp and install a better after market amp and speakers while I am it, but that is just wishful thinking.  I need to hook up the nav as my first priority.

The bottom line is that I have to do this myself as I simply can't afford to take it to a professional in as much as I would prefer to do that.

I am sure with enough direction I can do this myself. 

So far this is what I have found in my research:

There are 4 connectors that plug into the back of the factory amp. One plug has only 2 wires that go through it. That is the plug for the subwoofer

Car is a 1999 Lexus GS400

Audio equipment is as follows:

HU - Pioneer AVIC-D1 navigation system

Front component speakers - Seas Excel W15CY-001 (E015) 5.5" - but the older model in 6.5" - http://www.madisound.com/cgi-bin/index.cgi?cart_id=2241445.11217&pid=985

No rear speakers as I want to keep the sound stage at the front of the car

Tweeters: NeoCd3.0M 3" Ribbon Tweeter http://www.madisound.com/cgi-bin/index.cgi?cart_id=2241445.11217&pid=2139

Subwoofer : Focal Utopia 27WX 11 inch sub

Component Amp: Zapco Competition series - C2K - 2.5X http://www.zapco.com/prod/comp_prods/c2k25Frame.htm

Sub amp: Zapco Competition Series - C2K - 2.0X - http://www.zapco.com/prod/comp_prods/c2k20Frame.htm

Three SymbilLnk cables.

I don't have any crossovers and I was wondering how to physically wire these up - specifically the wiring of the amps and speakers:

I have already hooked up the navigation system (and it works flawless other than no audio as I still have to wire up the rest of system) and ran RCA cables for the speakers (front, rear and sub) all the way to the back. So my questions focus from that piont forward.

1. What is the basic path to follow from the beginning - 4 guage wire from + terminal of the battery all the way to the speakers in the doors.

Here is what I think I need to do:

1. Power cable from + side of battery

All negatives for the amps grounded

Here are pics of the amps connections (C2K - 2.5X) - How would I configure the amps to send their output correctly to the front speakers and tweeters when there are no crossovers?

C2K - 2.0X

Please confirm my wiring path and the questions regarding how to wire up the system. I am in over my head, but just can't afford to hire a professional to do this for me.

I think with guidance from the gurus on here, I can do this! I have looked at the amp manuals and I am still in the dark - [url]http://www.prudensconsulting.com/yahooitems/C2K_2.0X.pdf[/url]

I made an amp rack from 3/4 inch high density MDF and will be bolting that to section behind the rear seats - see this pic for reference: (this is looking into the car from the rear. You can see the nav installed if you look at the dash)

I have tons of sound deadening that I will install also. I also have to figure out where to install the subwoofer. If you look at the pic above the stock sub is on the rear parcel shelf, however that shelf is flimsy thin piece of metal and will not support the sub in a box (I bought this box for it (see below). If you look directly behind the rear seats in the trunk, you can see a raised area where I can install the subwoofer box, however my rear STB (strut tower bar) is in that spot. Any suggestions on how to install the sub box other than having to reinforce the rear parcel shelf and just complicating this install further?

This is the wiring I bought (already used up the RCA cables running from the pre-amp RCA outs on the navigation system). You can see the pic of the 4-gauge amp kit I got (and the rear view camera at the top - got that working very well already)

Since you have no passive crossovers for your speakers, set the crossovers in your deck to high pass around 80-100 Hz (about where you'll crossover the sub)front and rear- this will be your starting point.  Set the crossovers on the 4 channel amp to around 2.5 kHz for starters, with the tweeters on high pass and the midbass drivers on low pass.  A cd with multiple test tones will help you locate your crossover points, as well as setting gain.  Just run your speaker wire from you amp directly to your speakers.

It looks like you've got a grasp on the basic hook up.

Why do you feel the need to secure your box to the rear parcel shelf?  Why not just secure it underneath?  Just be sure of where you drill so as not to punch a hole in the gas tank or anything.

Chapter 8 goes over the audio controls on the deck.  Scroll down to where it says "Using the high pass filter".

http://www.zapco.com/prod/comp_prods/documents/C2K_Contents_Manual_B.pdf  Scroll down to where it says 4 channel amp controls.  The different controls are numbered, with descriptions of what each control does on the next page.  The front and rear frequency range buttons should both be pushed in so that you're on the crossover high range.  The pictorial will give you an rough idea of where to set the crossover frequency knobs front and rear, which you can check with your test tone cd. 

You connect the tweeters to the speaker outputs.  If you use the front inputs for the tweeters, then you'll connect them to the front speaker terminals.  If you use the rear inputs for the tweeters, you'll use the rear speaker terminals.

I'm not telling you it has to go where the strut tower brace is.  Why do you feel it must be secured to the rear deck?  Just place it in the trunk and secure it in place.  It doesn't have to go all the way back.

If there's anything here you're still not sure about after reading all this, have a friend that's done this before help you, or wait until you can afford to have it done (even if it's just a little at a time).  Otherwise, you could easily mess something up and see those hard earned dollars of yours go to waste.