Hameed

I need some help swapping out the Nak HU in a 99 GS 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 still have a few questions for the audio gurus. Is this the correct diagram http://lexusmodz.netfirms.com/GS_DIY/stereo/ ?

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 banana's website that identifies that cable behind the instrument cluster - so I think I can get to that one.

GS3Tek

iTrader: (8)

I'll jump in so it won't get too lonely here

I don't think that link will work for you Hameed.

He's keeping his stock HU while replacing EVERYTHING with aftermarket..
You're changing out your HU aftermarket while keeping EVERYTHING stock, is that correct?

For the headunit, that's the easy part.

There's usually 4 wires for most HU installation:
1. Constant 12v power-with a tester, this will turn on without turning on ignition.
2. Negative/ground-any metal part. If it's painted area, make sure you scratch all the paint good.
3. Remote turn on/acc-turn on with ignition in acc.
4. For nav-the speed sensor which you know.

Then you have to tap into the signals going into the amp. I believe tiguy has a link to that.
I'll come back if I can find it. Hope this helps somewhat for now

Hameed

Thanks bro!

Correct. I just want to swap out my HU and keep everything else (at least for now, until I feel more comfortable swapping out the rest)

Do you have any idea if it is easy to identify these wires on the Nak HU as well as the Nav itself?

I did a search and could not find this. When you get a moment, please try to find it and post it. Thanks again for all your assistance.

If I am able to do this, I will take lots of detailed pics and do a write up so that someone else can benefit from it.

SoCalSC4

Hameed,

I have this same unit for my GS... been sitting in the closet since the car went to the body shop, it's killing me!!! Anyway, did you get the OE mounting brackets & trim for it? I bought the OE Japan mounting kit from Carson, it includes a really nice dash trim piece which matches the OE grey 'stack' color..

I was originally thinking about doing the opposite you're doing... I have a bunch of Boston Acoustics stuff (GT-28, GT-42 amps, Z5 speakers front/Pro 4.5 rear, 12" Pro subwoofer) I was going to try to run with the OE Nakamichi head.

I did some homework on this (using the Nak head with aftermarket amps) and I was concerned about the output level of the stock head... I ultimately decided to step-up for the AVIC-D1. I am going to trash the entire Nak system, so I'll basically just need to tap the OE constant & key-hot power, antenna, and run the speed sensor wire. Everything else will be new Monster Cable stuff!

In your case, the trick will be getting the audio signal from the Pioneer head unit to the Nak amp. I would assume you could use the low-level outputs (RCAs) at the Pioneer and cut the end of the RCAs to splice them into the Nak amp, but I'm not sure what kind of voltage the Nak amp expects or demands. I'm not sure anybody but Lexus engineers know... also, the OE sub is run out of the Nak amp... I assume the NAK amp has four speaker inputs (front left & right + rear left & right) and the sub somehow gets its' audio signal from these, but I am not sure. You may loose the subwoofer output if the amp does not 'see' the proper audio input for it.

I do think the speaker level outputs on the Pioneer may overdrive the NAK amp, but I could be wrong. I have a few people I can ask about this, I'll check around and post my findings ASAP!

Good luck... and congratulations!

Bob

GS3Tek

iTrader: (8)

OK, I found one of the link ,credit to tiguy99 , but I think it's for a stock pioneer amp, not the NAK. However, it's the same concept......You need the find the input speaker wires. Basically if you are to pull out either the + or - of the speakers and that speaker turns off, you located it....just 3 more to go.
Worst case scenario you can use the speaker output from the d1 itself.

And pretty much what socalsc said above.

Where's percy or our audio gods???

https://www.clublexus.com/forums/sho...d.php?t=187864

Hameed

I got one from Todd at TM Engineering a while back, so will probably end up using this - still not sure yet... as I think it has two compartments in it as opposed to just one.
I hear ya! I have a whole bunch of audio stuff also sitting in my garage for the last two years, but just can't afford a professional install right now, so will not even attempt this right now.

Please post your findings as soon as you get them. Thanks!

Here is what I have gathered so far in my research (mainly searching here).

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

Black wire = +
Red wire = -

Now we move onto the big plug to the right of that one. This has all the speaker outputs.

Front Right speaker
Green = +
Blue = -

Front Left Speaker
Pink = +
Purple = -

Rear Right Speaker
Red = +
White = -

Rear Left Speaker
Black = +
Yellow = -


That blue/yellow wire is a 12v constant. It always gets 12v even when the key is off. The cigarette lighter can be used for the accessory turn on lead.


Do I need to buy a tester and any other "tool".

GS3Tek

iTrader: (8)

If you don't want to head out to your 99c store, just get any wedge bulb or any auto bulb (12v) connect it to the car metal body (-) and tap away for a +

Hameed

Thanks!

What about wire connectors etc and such? http://cgi.ebay.com/360-PC-Insulated...QQcmdZViewItem

GS3Tek

iTrader: (8)

Of course, all those necessary items if you don't them already. Your local hardware/radio shack/some electronic stores should carry them rather than ordering online.

Just a reminder that if you're going to cut wires, make sure you cut them far away from the harness/plugs.....you don't don't want those wires to get too short.

Don't forget beer and some tunes to listen to..........I'm not a beer drinker though

Hameed

Someone on the12volt.com suggested I get one of these: Soundgate XR4 http://www.sjgreatdeals.com/sgtxr4.html

Is it worth getting this?

corkycal

iTrader: (8)

i'm going to install this same unit in my gs. were are you going to tap into the speed sensor? any pics? i'm going bobs route getting rid of the stock hu and going aftermarket everything.

GS3Tek

iTrader: (8)

Don't know Hameed.
Why don't you try it without that first?

Anyone else out there?

engin_ear

iTrader: (1)

Got your PM on identifying the antenna. It's very easy. When you take out the Nak unit, there is a thicker black cable with a large metal connector that is plugged into the back of the stock headunit. Just pull it straight out. This plugs directly into the antenna-in connector of the AVIC-D1.

Hameed, there's no way I would ever do any audio work on your car without having a simple volt-ohm meter around. You can get one cheaply at Radio Shack, Sears, Wal-Mart, etc. It allows you to measure circuit/conection continuity, and check wires for voltage level, etc. $20-30+ for something reasonable.

Splices are usually done with "butt connectors" (no laughing please :-) ). For those you need a crimping tool. You can get these at Home Depot or Lowes or Radio Shack.
You can also solder wires from the new headunit to connect to the Toyota wiring adapter. To insulate them you need either heat-shrink tubing (better) or electrical tape (not as good - unravels).

corkycal

iTrader: (8)

on the speed sensor wire, where do you tap into this on the GS?

Hameed

Thanks!

Good idea, but if I disconnect the battery (as mentioned in the installation manual), how would I be checking voltage across lines anyway? Yes, I am full of stupid questions in this thread.

Thanks! I will pick up a bunch of those "butt connectors".

Speed sensor wire - Its in an 18 pin white connecter behind the instrument cluster - green wire - pin 6.

Credit to BananaGS http://lexusmodz.netfirms.com/ - go to DIY #14 for the "Interior" section to see his DIY on how to get to this wire.


Here is a pic of it (also from BananaGS's DIY)