here is the stereo wiring diagram for our cars
 

1st gen GS300 stereo wiring diagram

https://www.clublexus.com/gallery/da.../6361page1.jpg

https://www.clublexus.com/gallery/da.../6361page2.jpg

https://www.clublexus.com/gallery/da.../6361page3.jpg

YOU'RE WELCOME :D

Awesome info !!! Now all I need is to find some changer plugs to convert my GS from Non-CD to CD changer.

Ken

Cool, this is going to be really helpful:thumbup: Maybe this should be a sticky or it should be posted under the "Specifications" section for the 1st gen.

i don't think thats possible unless you wanna rip up all your carpet and run some serious cables. there are probly nearly 50 tiny little wires that must be run from the front of the car to the rear of the car. you must also change the headunit.

btw PIANOMAn you ROCK!!!!. i've been too lazy to go to the dealer to pick up the wire diagram to fix my antenna. after 2 years of aftermarket sound system my antenna has not gone up yet. but today will be the day. lol.

i tried connecting all 3 wires on the blue plug 4, 9, 10 all to the antenna wire on my aftermarket headunit. but the anteanna is not coming up. the headunit is in radio mode so it should go up, but no go. i also tried different combo of the 3 ant wire but still no go.

Jmai, try this:

In the trunk at the antenna, splice together the Red-Green and the Black-white wire.

Now at the headunit try hooking into the three ANT wires, one by one. I think one of those combos will work.

BTW Ken if you don't have the "CD" button on your HU you have no interface (plug) for the changer on the back of the HU. Sad, but true.

walking out to the car now.

here's a few pic. first thing i notice is there is no plug here. can someone verify this. i checked for extra plugs but there is not one.

this one? and where's the other on that same harness?

or did you mean to splice these 3 together?

Don't make me bust out the digicam, too, jmai. lol

Here's a pic of mineS to look at. Give me a sec to figure this freaking deal out. Yes that wire is the AMP wire you circled and the SC guys used it somehow to get their antennas working. i don't see the black-white wire which troubles me. hmmmm.....

oh man, you busted out the digi. i appreciate it man. this thread will go down in history. this is a perfect DIY aftermarket headunit instruction. we are slowly tearing the first gen gs apart. lol. this forum could be the First gen gs complete DIY booklet.

Jmai I think you want to cross the RED-GREEN that you circled with the BLACK-YELLOW wire. That should give the antenna power and then you can use the ANT output from your aftermarket headunit and connect it to the BLACK-WHITE wire (pin 9) up behind the headunit. Total longshot.

oh yeah, ABOUT freakin time you checked the forum. lol. i been waiting for you to reply. thanks lol. like all my sound deadening materiel? my trunk lid weights a ton due to the same stuff all over my trunk plus foam

ok going out now. brb.

NO GO.i ran a wire from the blue line and still no go. i tried all 3 pins on the headunit too 4, 9, 10

You could try both pins 4 and 10 together? Where did you find that post anyway where the SC guys were talking about what wires make the antenna go up. I have both diagrams; it's back to the drawing board but I can't find that post....

Also, both the BLUE-YELLOW and the BLACK-YELLOW wires going into the antenna are labeled +B. WTF is up with that.

Maybe crossing the wires back at the antenna was a bad idea on my part. If we are supposed to trigger some stupid "antenna relay" and we don't know where it is, we should probably stick to the wires behind the HU.

That deal that is not connected is probably that "telephone transceiver" thing.

OK if you are just joining us, HELP. lol.

FACT 1:

We have three wires:

ANTA ------ BLACK-YELLOW
ANT+B----- BLACK-WHITE
ANTB ------ BLACK-ORANGE

FACT 2:

We need to trigger a relay

SOMETHING THAT MIGHT BE TRUE:

The SC guys reportedly used the "AMP" wire somehow (RED-GREEN).

SOMETHING THAT IS MOST DEFINITELY TRUE:

Jmai's antenna has not moved for two years.

There now everyone is up to speed.

https://www.clublexus.com/forums/sho...hlight=antenna

here's one of the link. there's a few more let me dig more. you sound like you knew what you were talkinb about here htough .lol.

i tried connecting the amp wire pin3 with each of the anteanna wire and still no go.

OK this is what HE did in that thread so I'm taking it for OUR CARS but our diagram is labeled differently.

1) Take the ANT lead from your aftermarket headunit.

2) Connect it to freaking pin #3 RED-GREEN ***AND***

guess 1 --- pin #9 BLACK-WHITE (ANT+B)
guess 2 --- pin #4 BLACK-YELLOW (ANTA)
guess 3 --- pin#10 freaking BLACK-ORANGE

Don't mess around in the trunk do this behind the HU.

3) Pour coke on antenna

4) hit with hammer

Already? Dammit. That makes no sense. I thought for sure we would get it working. Oh well the diagram is on here. Sorry, man.

yup did that, no movement nor sound coming from the anteanna. do you have an aftermarket unit? how did you do it. i know its possible Patrick(indypwr) has done it. but i also forgot.

thanks for the hard try though.

I have already purchased a head unit that has CD-changer capability. And am waiting on a changer.
The only "Cable" I should need is the interface cable that provides signal and power from the deck to the changer. Unfortunately that is part of the main wiring harness and will have to be custom made, I am waiting on the maker.

Ken

What's the going rate for a 1st gen GS radio with the cd button? I've never seen one for sale on CL. Yeah probably want to make your own cable for the changer. METRA might make a plug that fits or you could source one from a different Toyota model. Hopefully Toyota CD changer cables don't vary that much. I remember some guy with an LS did make his own cable and I think he had an aftermarket changer, too.

for my aftermarket head unit i just connected all three wires that were on the stock headunit to the "pwr antenna" lead on my headunit and it works fine.... Btw decent job on the sound deadening hehe, but i've got 200 ft^2 in the lex too :D The roof was a hardest to do me thinks....

ROOF? you crazy guy. i used about 3 cans of expanding foam in my trunk, trunk lid, and rear deck, also about 150 or so sqft in my trunk and rear door. and entire back seat.

Gompka, do you remember if it was pin 4, 9, 10 that you used? i'll try again tomorow with some better wires.

I got mine for $150 from eBay. I have only found the one on there though. But I am sure that they pop up from time to time.

Ken

My sub comes out of the rear deck, i have 0 vibrations in the trunk with only 2 layers on sides and lid. All the sound goes inside, but since the sub was on the rear deck my roof was flexing crazy so I had to rammat that. My doors is where most of the mat is though like 4-5 layers on each one:D I don't remember really what wires they were, i think they were the 3 wires that are left over after you install the aftermarket unit. I thought it was strange too but i put them all together with the pwr antenna lead and it works like a charm, antenna goes all the way out though, doesn't adjust itself like with the stock unit.

Guys, I understand that the Toyota Amplifier Interface (Metra # 70-8112) is the part used to connect to connector R2 in the diagram. But then, what is the purpose of connector R3 which is Blue in color? Metra does not seem to sell a plug corresponding to this connector.

Thanks,

Brian

I added a bunch of photos and info about 70-8112 to the aftermarket stereo faq here

https://www.clublexus.com/forums/sho...t=89612&page=3

Still trying to figure out how to make the factory antenna go up with the antenna lead on my aftermarket deck. Did you guys ever figure that out ?

Thanks,

Brian

ANTENNA TURN ON TO BLACK/WHITE WIRE in BLUE PIN BLOCK FOR ANTENNA UP
 

Guys, finally figured it out. Funny that I couldn't find this info anywhere by searching, and also found a lot of mis-information about other wire colors.

On a 1993 (and probably all the way to 1997) GS300 w/ Pioneer, you attach the ANTENNA lead from the aftermarket deck to the BLACK W/ WHITE STRIPE wire in the Blue OEM 10 pin connector. Antenna goes up with radio, and down when headunit is off or in CD or AUX mode.

Also, you will see two antenna leads back there. You only need to hook up the larger one to your aftermarket deck. Tape up the smaller one and stuff it in back. The smaller one is called a diversity antenna, and was Lexus' attempt to get better reception. This is why your antenna normally goes up and down depending on what station you tune to on the stock deck.

If you have ALTERNATOR WHINE you can either use RCA GROUND LOOP ISOLATORS (radio shack), or you can ground all of the individual speakers to the cars frame, or a common ground. I've been told the GROUP LOOP ISOLATOR route, which I used, negatively affects sound quality. But, heck, I can't tell the difference...

Good luck...

Brian

My friend has a 1994 gs300 and he recently just had a cd player put in that he did himself.....now everytime he turns on his car he has to reprogram his car clock and his radio clock. It never stays programmed.....any suggestions guys?

thanks for this!!!