I was trying to fix the cigarette lighter in the center console on my 2000 ES300 and I came across this wire harness.





I then got intrigued, because the only thing I thought of, that could possibly go in that location would be a PHONE! So while I was in there I wanted to see if it was hooked up to anything. With a test light grounded I tested the pins and I found that the harness is wired to silence the radio, and bring power (as seen in attached video).

Now I'm genuinely interested in the possibility of wiring up a modern Bluetooth handset using the factory radio and car phone wiring. I also am going to try and wire this handset, to be used as a hand piece with the eventual setup. Since I have nothing but time, I want to try to attempt this bada** mod to my ES.




If anybody has any information regarding this harness, or any wiring for the cars equipped with a car phone, that would be greatly appreciated.

Thanks in advance!

 

What do you mean by bluetooth handset? Those retro things?

 

No, its basically a cell phone to landline Bluetooth adapter. It turns cellphone call audio into an analog signal. I (think) I can then wire the input and output sound, along with power from the device to the handset and possibly speakers. This would give the effect of a modern system, since it would be pausing the radio when calls come in (Theoretically)

Bluetooth handset was poor word choice,

 

Ah, would be neat if it would integrate and work like that.

 

Going to try, but I'm still trying to figure out where all of these wires go. There is some sort of plug on the left side of the steering wheel under a cap (possible mic lead?) Also I need to figure out if the wires shown in the video will actually send sound to the amp, because it mutes all audio without pausing or effecting the stereo. I find it very interesting that Lexus left all of this wiring intact even if it wasn't a chosen option. I guess it makes since from a cost standpoint.

 

After many months of research (and not really being focused on this) I finally found a solution that met all of my aspirations, going into this project. It was pretty difficult (aka impossible) figuring out all of the wiring for the stock car phone. I was able to figure out that one of the wires on the harness in the car cut power to the amp, when grounded. The other two were power and ground. I then researched other car phone options from circa 2003 and found out that many porsche and BMW dealers actually installed Nokia and Motorola car kits back then. So, I got the idea to try something along those lines, and it worked flawlessly.

I found the Nokia CK-7W car kit new in box from Norway. I chose this particular one, because it was one of the only ones produced that integrates Bluetooth. It wires right into the factory Lexus car phone harness. It has a relay inside that can cut power to the stock amp when there is an ongoing call. It also works flawlessly with my modern cell phone (Sony Xperia XZ1). Now I can also say "Okay google" and the stereo will mute and I can talk with the Google assistant. It also mutes the audio when giving navigation commands.

All phone audio comes through supplied loud speaker, which I mounted behind the ash tray.

P.S.
I don't know if anyone else cares about this. But I think it's incredibly cool to find old things like this and keep our older cars operating with stealth, stock like features. I realize it would have been easier to just get an aftermarket radio... But I can't give up the CD changer and still listen to cassettes daily. Not to mention the factory radio is gorgeous, when compared to modern radios IMHO.
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