I know this has been posted before but I have not been able to find a clear answer and would appreciate all the help you guys can provide before I rip my dash apart. After my second lexus cd changer died on me this morning I have decided to go with an aftermarket head unit. However I cannot locate a scematic or diagram of what each wire in the harness that plugs into the back of the head unit is.
If anyone has a color coded list of what each wire in the harness is or if you have found out by installing an aftermarket unit yourself, I would really appreciate that information. I have the Lexus Premium System (pioneer) with the seperate amps for the speakers and one for the sub.

Thanks in advance for your help.

 

I feel for you man. I'm the one who originally posted. Still haven't got confirmation on the wires. I'll probably get in there this coming week with a voltmeter and do it myself. I will be glad to post my findings.
You would think that with as many people who have replaced there head units that someone would be able to post this info. I've actually been getting more answers to questions on the GS forum. Not wanting to start anything, but for as many cars as we have out there, there isn't a lot of information be provided. There, done venting!!!!

Shane

 

I haven't and don't know how to change the head unit in SC. I am sure like to know how to do this too. Factory Nakamichi had die on me once and CD changer twice
I just bought the electrical but don't have time to read up yet; therefore, can't help you now because I don't know what page to read up yet. If you can wait for a while, I'll look it up, copy and fax to you. It's going to be a while though. You can also buy it from Carson Toyota, cost me $25 for the electrical manual.

Right now I want to spend time on look up the wiring to hook up a Fog Lights. The 93SC400 head light sux and I don't want to rewire the signal light. It doesn't help me on foggy days

 

Do they make aftermarket harnesses?

 

Ok bro, what are you installing and plan to do? I will be happy to get you the info you need. First check my web site to see if that helps. If you are planning on using your existing speakers and amps then it will be a bit more difficult. Much easier to replace all.

You can use your existing head unit and install an aftermarket CD which uses RF to get the signal to your head unit (not that great but cheap and easy and ok for nonaudiophiles).

You can replace the head unit with 1 din unit, then you have a 'hole' in the dash to fill with a pocket, plastic or another din unit. Either way you will need to do some custom work. I currently have a guy in Taiwan working up a quote for my own lexus stereo dash design - it is still a few months away from availability. Install is easy for DIN, no mounting kit needed, the frame has holes in the right places to slide in your DIN.

The head unit can be wired to turn on and power the stock amps and speakers. You must use the RCA outs and DO NOT use something with high >4.4 volts output or you may fry the stock amps. The stock signal to the stock amps is full range to all except the sub which is Low level.

This means you can just wire your rca's to the stock harness - email me for diagram if it's not on my website. You can wire your remote turn on to the stock harness, If you want to do the extra work, you can wire in series with the volume control and use the Lexus volume ****. I use mine with my Epicenter to contol bass.

 

OK, OK. Moshlub, VQT, SSmith, SCream 400, here's the colours for the wiring, you owe me Shane! This is for the Nakamichi premium system, but since the colours are pretty much standard Toyota, you can use it as a reference for doing the Pioneer, the order of the pins may be different, etc, but this is enough to help you figure it out. An aftermarket adapter plug is not available, one of the Toyota plugs fits I believe, but the wiring is a bit different. Here's what I did; not wanting to cut the harness at the receiver plug, I just tapped into the plug in the back for the factory amp, since that's where most of the wiring to/from my amps runs anyway. Simple, easy, painless. As far as a trim piece for the receiver, the entire space is a full 2.5DIN, so if you use one single DIN receiver, you'll have 1.5DIN of space left over. I mounted an Alpine CVA-1005 in the uppermost space, and mounted a single DIN digital signal processor in the glove compartment, upholstered to match. For the 1.5DIN space below the Alpine, I had a guy in California make me a panel with 2 layers of carbon fiber and a layer of fiberglass in the back (so it'll be strong enough to hold gauges later). I had to trim the panel to fit, not an easy job cutting carbon fiber, but it was well worth it. In the ashtray, I made a little 'James Bond' switch panel from textured ABS, using trick RH-style switches. This controls the purple neon in the amp rack, the 140/300watt power inverter for the Playstation2, and my 'hotwired' handbrake switch (the Alpine, and other motorized monitors, must have the parking brake engaged in order to watch a DVD, so the driver can't watch while he's driving, I have remedied this). I'll post some pics when I get a chance.

Remember - this is for the plug at the OE amp:

Left front mid + Pink
- Violet

Right front mid + Lt Green
- Blue

Front tweeters are split off from the door speakers post-plug

Left rear mid + Blk
- Yellow

Right rear mid + Red
- White

Sub + Supposed to be red w/ wht stripe, mine was -
- Supposed to be wht w/ red stripe, mine was +

Now, someone find me a '92-'94 front spoiler! Shane, you listenin'?

 

Thanks Lex Luthor

 

Hi Guys,

Thats some good info on the wiring specs, as I was replacing the whole lot I rewired everything from scratch. The big problem I found was the size of the hole after removing the factory hi-fi, it's not just bigger than double DIN but it's not flush sided and slopes in several planes, for now I wedged in the CD player and a pocket (from a Renault), it still leaves a 1/4" gap above the ashtray but I will be fitting boost gauges later so I will make a custom panel.

Wanting the new hi-fi to look stock was the aim, it's not easy to find new equipment in black so I searched all the catalogues and located the Becker CD Pro (it's the dogs bollocks), the only thing it doesent have is green illumination (Orange or Red, reversible display).

We are trying to get a double DIN hi-fi surround from Japan for the Soarer (SC300/400) - still waiting though.

 

Hey guys thanks for all the feedback.
Lex Luthor, thx for the color codding and 933005spd I was thinking of using a double din unit since that will leave a smaller space to fabricate a cover for. Also I will probably rewire the speakers since most of the units I was looking at have built in amps that brobably put out more power that the stock amps.

 

933005spd! you are the stereo experct! as far as sc300's go.. ok i have the same setup as you, pioneer/12disc changer.. i dont care about the changer all it dose is skip like crasy.. but i would like to leave it there for returning to stock. , now what i have is a deck already its a non-powered head unit, which means i need to have an amp hooked up to it.. but from reading some post it seems i can intergrat the current amp built into the car to my new deck. the new deck has two 4v pre-outs.. i wondering if this is too much for the amps to handle? also this is a single din unit am i going to need to make a mounting kit or cut one that fits another car? im pretty experiencd with car install.. but i can tell this is going to be a project since there is minimal information about it.. and you seem to be the guy with idea.. and im willing to pay you for your expertise.. i already donated $1 to your paypal fund.. so email me or PM on the forum ill be around all day.. wondring if i should contiune or not. thanks

 

Well I got it all in thanks to all you guys. Also 933005spd is definitely an expert he helped me along the process and even showed me how to use the old volume **** as a bass output control so now I can control how much bumb I have depending on who else is in the car. Heres a pic sorry its low res but its a ****ty camera.