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· Useless
4,800 Posts
If any of this information proves useful to you, please take a moment and Rep those who took the time to share this.

The very first and most important thing to remember in this section is that your question most likely is NOT original. Most everything has been discussed to some dgree at some point in time. Please read through the information located in this thread and if your question is not covered then please use the search button located at the upper right of the screen. Try different search phrases and you will most likely find the answers that you are looking for. It may take you a little more time to find, but at least you are learning how to use search. It beats waiting for someone to answer you and you get the self satisfaction of finding it on your own. If you feel that you have a topic that should be added to this sticky then please PM one of Moderators so we can add it with a correct answer so those who view are not mislead.

"OMG...everything is so confusing! I wish there was a flow chart to help me make decisions!"
Your lucky day----->Newbie Audio Upgrade Diagram - MUST READ FIRST


Information Section: This is the place to read up and learn something.

Taking Stuff Apart
Dash Disassembly Steps
How to remove Rear Seats
Getting to the Rear Speakers
Getting to the Front Speakers
How to remove stock headunit, unjam CDs

Rear Speakers...the Saga
Why the stock rear speakers won't work with an aftermarket headunit.

Navigation and Screens
Stock Nav screen size = 7"
Adding Navigation - Options
Stock Navigation needs 1 PCB from stock headunit to function with aftermarket headunit
Factory Navigation; How to install aftermarket screen into OEM Nav housing
Pioneer AVIC-D1 review / issues


DIY Section: This stuff will help you get the job done yourself.

Car Audio and IS300 Mods: The Necessities
Car Audio Basics
Entire Audio System Overhaul DIY w/ step step instructions
Selecting proper wire gauge
JDM Dash Kit without heated seat / trac buttons relocation
Detailed Radar detector installation instructions
Weak spot in stock security system; How to improve it
How-To: Keep 45 Sec Moonroof and Driver Window open/close delay if any door is opened
The "Speakers that Fit" thread.

Stereo Wiring and Amps
Partial DIY of Metra Harness and New headunit install
Wiring Diagrams(see post #29 for updated links)
How to install an amp for the two front channels and how to deal with the NAV relay; Radio Diagram Pictures
Factory Pre-Outs
Thumping sound from amps; ground loop isolator
Bypassing the stock amp wiring guide - DIY
Adding a sub and keeping the stock headunit
>>>Updated link for adding preouts to stock headunit>>

More on wiring diagrams > > >

Use attached diagram for keyless entry with after market security/ remote start units.
\/ \/ \/ \/


· Useless
4,800 Posts
Peter_Klim said:
How do you remove the rear seat bottom and back?
The lower part, you just grab the front side 1/4 the way in from the edge and lift. It pops out of a plastic holder. Duplicate on other side. The rear is held in by 4-10mm bolts. Also use a 14mm and undo 3 of the 4 seat belt bolts. You will see which 3. Then lift up and out. You must lift kinda high and it will come right out.

ItalynStylion said:
Rear Seat Bottom- The bottom pad must come out first before the seat back. The pad comes out by grasping under the pad closest to where it is attached on either side (pictured below) and pulling up. The pad snaps in and is difficult to pop out, this will take some force.

Rear Seat Back- Remove the headrests. Once the rear seat bottom is out the bolts that hold in the seat back are exposed and accessible, remove all four bolts. Then grab the seat back and slide it up against the metal backing to get it out of where it slides in and is secured at the top. Add it to the pile of car parts you are making.

· Registered
346 Posts
Getting to the rear speakers:

Remove the the back seat and the rear deck lid. The rear grilles are attached to the rear lid so it has to come out.

Rear Seat Bottom:
You would have to first remove the bottom portion of the rear seat. It is simply held in by two pop-in retainer clips; one on either side. Lift up on each corner of the bottom seat until it pops out of its retainer clips.

Rear Seat Back:
Once the bottom of the rear seat is out the the C-pillars are next. There are 5 clips for each, three along the edge towards the front of the car, and two in the middle. Just use a panel removal tool or butter knife or something to pop them out. Once the clips are popped out, the covers slide forward and out. Once you've taken the C-pillars out the rear seat back is next. It's easy to unbolt but hard to get out. Unbolt the four bolts located on the bottom of the seat holding it in place. Some people unbolt the seatbelt clips. I did not. The seat is held in place by clips on the top of the seat that slide in to place downward when putting the seat back on which means to get it off, you need to lift, rather hard I must say, to raise these clips up and over their retainers. You can remove the headrests if you think it'll make matters easier.

Rear Deck Lid:
The deck is a pain in the ass to both remove and reinstall. It is held in place by two different means. First remove the covers to the three tiedowns on the deck lid and unbolt them. This might also be a good time to make sure the seat belts are out of the lid fabric and hanging below it. Second, and this is the pain, you need to unclip the sides of the deck lid. The lid has four slots, two on each side. Into these slots slide plastic tabs that are connected to the car on each side. I removed the tabs a pretty dirty way, I used a screwdriver to weasel my way under them and pull the lid out. It took a little while but I got them out. The deck lid now just slides out once you unplug the brake light.

Good Luck.

· Registered
346 Posts
Getting to the Front Speakers: (by TeCKis300, lisnup65, and DHCrocks)

TeCKis300:First thing to do is to take off the door panel. There are two screws on each door that need to be removed: one at the bottom of the arm rest pull handle, and another behind a small cover in the door pull release handle. There are then 8 plastic snaps along the bottom and sides of the panel. Take a butter knife and cover it with a piece of cloth (to avoid scratches) and wedge it along the edge. Pull the edges straight away from the door. Once you get them all off, remove the trim piece around the door release handle. This is done by wedging a flat screwdriver and pushing the trim up to release a tab. There is another at the bottom edge also. Once the tabs are off, you should be able to slide the trim off towards the open edge of the door while pulling the door handle. That's it. The door panel should come off by pulling it away from the door gently while sliding it upwards. Don't pull it completely off because you have to unplug the wires for the power window, locks, and courtesy light.

Now to remove the stock speaker.

Unplug the wire.

Get a drill and drill out the 3 rivets in the door. After the rivet head comes off (including the plastic piece behind it), you should be able to pry out the speaker. The rivets themselves will still take a bit of effort to drill out. Some will pull out and some will be pain...just keep going at'll come out.

You can choose to make a speaker mount/baffle from 3/4" MDF
You can use the stock speaker riser mount which is an integral part of the speaker basket. This part really sucks because you'll have to totally destroy your stock speaker to recover the baffle/mount. That's unless you choose to make one, which is recommended. If you have the time, 3/4" MDF would work nicely.

Get a utility knife and cut out the foam speaker cone surround. Then turn the speaker over, get some cutting pliers and cut each basket post. Also, cut the wire lead that goes to the socket. Then the two pieces should separate and now you have a mount/baffle.

Once that's done, you can pull out the white wire socket with pliers. Next, you'll need to pull off the foam surround. This is necessary because if you just mount the speaker on there, it will be too tall and hit the door panel/grill. Slowly go around the whole thing with pliers and pull it off. Once you have that off, you can mount your new speaker directly to it with some screws. It should screw in there nicely without even drilling any holes. My Infinity Perfect speakers had a 2 3/4" mounting depth and they fit fine. There was a tad more clearance in the rear so you may even be able to get away with 3" speakers.

lisnup65: Actually the depth is dependant on the speakers that you choose. To properly get the mounting as it was factory (Flush against the door panel), you need to use a 3/4" piece and a 3/8" piece coupled together to give you the same build up that the factory speaker gave.

TeCKis300:Note about the crossover. The crossover that came with my set was relatively large. A good place to locate this is in the door panel itself. If you look at the backside of the panel...there will be a large foam piece. Rip that out and locate the crossover there. I chose to use Velcro to attach it to the door panel. It fits snugly there once the panel is put back.

DHCrocks:To affix the speaker to the door, you can use a threaded insert. Basically all you do is drill a hole into sheetmetal and insert the fitting. What it does is provide a threaded sleeve so that you can attach machine screws to. They come in standard sizes like 10-24 or 10-32. The first number is the stud size and the second is the thread pitch (ie: 24 threads per inch). it is a fast way to make a removeable mount in sheetmetal, which is fairly thin and usually strips fairly easily if you try to use a screw tapped directly into the metal and torqe it down too much. It is good to use in blind locations where you can not get to the back to hold a nut. You can get it at places like HomeDepot in the hardware section.

Pictures and other details here.

· Registered
6,374 Posts
How to install an amp for the two front channels and how to deal with the NAV relay.

my.IS - Lexus IS Forum - Head to Amp connections

Also, correction on how my sub is hooked up. You cannot use the front channels to supply the signal for the sub as it is high passed in the stock amp. You need another LLC to tap off the rear 6x9 channels for the sub input.
(More stuff on how to install a sub with the stock headunit --->

Wiring diagrams:

· Registered
6,374 Posts
Stock NAV screen is 7"

· Registered
4,579 Posts
This is a post from another thread that I thought should be here:
lisnup65 said:
I jus did an install in a '02 IS300 without Nav. I put in an Alpine indash screen/tuner along with a DVD changer. The customer only added a sub amp and enclosure, the remaining speakers were the fcatory setup. His alpine is powering the front doors and the rear high freq speakers. He opted to leave the 6*9's out. I crossed over the the rears at 1000 hertz as they are only 2" paper cones, and the front at 90 hertz. The sub is running 90hertz and down. The customer is all upset because a moderate volumes the fcatory speakers start to distort something terrible. They are very cheap and the Alpine power actually is greater than that of the factory amp, thus the problems with power handling and distortion. I post this for those of you that are looking at doing this setup. I just want to prewarn that disappointment may occur.
Cliffs Notes: It will sound like crap and you'll eventually blow that shit up.

· Useless
4,800 Posts
Discussion Starter · #12 ·
Re: Rear 6X9 woofers are not getting any signal.

jeffmonk said:
I recently hooked up an amp and Enclosure off of the leads in the trunk that are connencted to the 6X9s. They worked for a brief period then quit. Now I am only getting signal to the stacked tweeters, and no signal from t he leads I had been using. What ccould have happened here. PLEASE HELP!!!!!!!!!
It sounds like the channel in the amp that provides the 6*9 signal is out or damaged. This can happen if you use a cheap LLC that adds resistance to the line. I only recommend Pac and Sound Gate LLC's as they do NOT add any load to the line.

· Registered
104 Posts
i know this is a late post, but i figured it might help you people out. for all of you installing an amp or getting a thumping sound from the subs even when its off, its more thank likey a bad connecting somewhere, i have gotting it in the past. i simply installed a rca ground insulator from radioshack. it actually worked great. and its only like 20 or 30 bucks. so if you getting any noise like that, try it, if it doesnt work just bring it me if you decide to try it

· Useless
4,800 Posts
Discussion Starter · #14 · (Edited)
I will cover the 6*9 problems once again.

The rear 6*9's in the IS300 prove as a problem point for installing an aftermarket deck. The reasons behind this are simple, and I hope this helps those who need it.

The 6*9's are not a conventional 2 way speaker. The woofer and tweeter are 2 sperate units. The woofer is a 2 ohm speaker that is powered from the factory amp through a cross-over. The reason behind the 2 ohm configuration is that it will receive around 2x the power as the other speakers in the car. The channels that drive the woofer also drive the mid/tweeter through its own internal(in the amp) cross-over.

When changing the speakers if you do not get the same type of 2/4 ohm configuration, you will lose response as the power of the stock amp is pathethic.

If you hook up a new deck to the 6*9's the problems are exactly as ststed. Your new deck does not have the built in x-overs to properly power the speakers and 95% of the time, your new deck is NOT designed to run a 2 ohm load. So if you have 2 channels for rear sound from the deck, how can you run them to the 4 channels of the 6*9's?????
It is possible, but you must create a hand built cross-over network. The lowpass filter needs to be designed for 2 ohms and the high-pass needs to be designed for 4 ohms. The problem is that it will cost you almost as much to create the network as it would to replace the speakers with real ones.
Again you must deal with the fact that your new deck is rated for a 4 ohm load and not a 2 ohm load. You may be able to hook up and run at 2 ohms, but the life of the cheap output chip in the deck will live a shortened life.

Now if you do hook up the 6*9's as many claim they are doing. The sound is horrible!!!!
Without the x-over network, if you connect the 2 and 4 ohm speakers to the same channel, the new deck would see a 1.33 ohm load which is a BIG no no. If you series the connection it would be 6 ohms which the stock deck would work fine with, but you still have the issues of sound. The woofer would receive all freq which makes it sound like ass, and the mid/tweeter would also receive all freqs which leaves it open to blow as it is not physically possible for it to produce a 90hz tone without damage.

To sum this up.

Change the speakers as the sound and problems the factory speakers create is not worth the $100.00 and up you would spend on new ones.

For those who want to make the x-over and use the factory speakers I highly recommend a 12DB x-over on the tweeters and woofer. The woofer would also work with the cheaper 6db x-over.

For the rear mid, I recommend to cross-over at around 1K HZ.

You will need 2 each of the following to create a 12DB 900 MHZ high-pass x-over.

Coil = 1.00 millihenries
Cap = 31.25 Microfarads

The cap goes in the positive line, the coil goes between the positive and negative speaker lead after the cap!

For the woofers, a 250HZ 12 DB filter will require 2 of the following:

1.8 milliheneries coil
225 microfarad capacitor

The coil goes in the + line with the cap wired in series(connect to both + and - speaker leads) after the coil.

This will allow just mid-bass and bass to reach the 6*9's and you headunit will see a 2 ohm load. The mids are protected from lower octave that will destro the delicate paper cone and the headunit will see these freqs at 4 ohms.

You can do as above, but with a 6DB on the woofer. Use a 1.28 coil in the + lead to each woofer.

See how it is easier to just replace the cheapo factory stuff!
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· Moderator
8,852 Posts
It seems that links in the wiring diagrams thread link I always post are no longer working.

I went ahead and uploaded 2001 and 2002+ WIRING DIAGRAMS to my hosting service. I'm not sure how long I will keep them there. The hosting service is set to expire in a few months.

Old hosting exired. Updated with new hosting links.

Right click, save as:

<-- Make sure to Click on
under my name and give some rep. :rebel:

· Moderator
8,852 Posts
wingzero's instructions with pictures on HOW TO REMOVE THE STOCK HEADUNIT.

wingzero said:
Okay, not sure if there is already a post on this but here it goes anyway:

1. With a flat head screwdriver, pop open the top part of the cloth plate.
2. You will see two screws like this, that you need to remove:

3. When the screws are out, that whole top cover just pulls out, you may have to use a little force.
4. The cover with the TRAC OFF and two seat warmers just pops out if you pull it hard enough.
5. Disconnect all connections.
6. You will see two bolts on top fo the AC controls and two bolts under the radio like this:

7. Remove the two bolts they are 10mm bolts.
8. The whole console just pulls out.
9. Disconnect the back connections, there should be 6 connections, 4 on radio, and 2 on AC controls like these:

10. This is what you should have when it is all out:

11. There are 8 screws total on the radio part, 4 on each side, you can either remove them via a Phillips screw driver or 8mm socket.

12. Remove the radio and then you should see 2 small screws that you must remove to get inside.
13. Once the lid is opened, simply remove all CD's carefully and make sure all the black trays are aligned properly.

14. To reinstall do everything in reverse. Whole thing should take you 15 min.

Mods, not sure if this should be in a sticky or How to FAQ's but since alot of peeps have asked this I thought I would be cool to have some pics to go with the procedure.
A tip from me:
Whether you are going to do it yourself or take it to a dealer for repairs, be sure to apply masking tape on the dash area, to the left and right side of the CD Changer/AC controls. This is to prevent your dash being scratched. It is almost impossible to take the headunit out as it is without doing some damage to that area. You may also put some masking tape on the shifter ball, as it has gotten some damage in the past too.

Here is my original post from while back on how to fix jammed CD changer.

Watch your fingers when working on the CD changer. There's a report of metal being sharp and you may cut yourself if you're not careful.

More of the process for disassembling the dash here...




Easier done if the seats are removed...

Usually only takes about 1-2 hours, assuming you are good at stripping cars.

#1 Disconnect Battery, Do Not perform work until 5 mins pass.

If you let the car sit without power for 5 mins you lessen the chance popping your airbag. Once the airbag is disconnected your safe, as long as you aren't jacking with it!

You will not need to disconnect the drivers side airbag.

#2 Remove Glove Box by removing the two plastic pins at the hinge and the 10mm/phillips head bolt.

#3 Remove Glove box hook bracket by removing the two phillips head screws, and the 10mm bolt.

#4 Using a pair of needle nose pliers, squeeze the airbag wire retaining clip out of the glove box hook bracket.

#5 Now that the harness is free, unplug it by pulling back the white tab on the plug. Now you are pretty safe from deploying your airbag.

#6 Disconnect the glove box light switch. Shown in step #3

#7 Remove the clip that holds the wire loom in place by wiggleing it back and forth with pulling.

#8 Now the wire loom should be free.

#9 Remove the nuts (2 10mm) and bolts (2 12mm) that hold the airbag in place.

#10 Remove the black passenger door sill panel.

#11 Remove the black plastic push nut from the passenger kickpanel.

#12 Remove the kickpanel by pulling towards you. Then remove the 10mm bolt that is revealed.

#13 Remove the cloth dash tray panel by prying the front of cloth covered panel with a pick or small screwdriver. Use a folded paper towel to protect the plastic.

#14 Remove the two phillips head/10mm screws that are revealed.

#15 Remove the dash tray by pulling straight out, it will take some force.
#16 Remove the 10mm nut, the 10mm bolt, and the top 2 10mm bolts that hold the AC/Radio bracket in.

#17 Remove the trim panel that holds the 'trac' switch buy applying pressure the the underneath side, and pulling straigt out.

#18 Remove the two 10mm bolts that are revealed.

#19 Now remove radio/ac unplugging the wires before you pull to far.

#20 Remove the 10mm bolt thats revealed.

#21 Remove the leather e-brake boot by first setting the e-brake, then pulling up the boot (pinch the leather on both sides of the e-brake).

#22 Start to remove the center console by removing the 2 phillips head screws on both sides of the console, the two in the pocket behind the e-brake.

#23 Now Remove the trim panel that holds the cig lighter, and ashtray by prying up around the chrome ring that's around the shifter. Once loose use your hands to pull up the rest of the panel. Unplug the cig lighter, cig lighter light, and ashtray light.

#24 Now remove the two phillips head screws that are revealed.

#25 Remove the center console by pulling straight back. Once loose lift it out of place.

#26 Remove the phillips head screw that is revealed.

#27 remove the access panel thats under the steering column by removing the 3 phillips head screws that hold it in place. Unplug the temp sensor and hose, remove diag plug, and remove hood cable.

#28 Remove the bottom portion of the steering column trim by removing the three phillips head screws. One is on the bottom of the trim panel. The other two will require turning the steering wheel right or left. Once screws are removed, gently pull the bottom off.

#29 Remove the 4 14mm nuts that hold the steering column in place. Let the column drop and rest on the metal cross brace below the column. The upper two are easy to spot, the rear two are harder to get to, and will require that you push the tilt spring out of the way with your socket.

#30 Remove guage cluster trim by removing the 2 phillips head screws. Then pulling out slightly until free. Unplug dimmer wire.

#31 Remove the 3 phillips head screws that hold the guage cluster in.

#32 Remove cluster, unplug the 2 harnesses. Once removed, remove the 10mm nut that is revealed.

#33 Unplug the light sensor harness.

#34 Remove driver side black door sill trim.

#35 Remove black plastic push nut from drivers side kick panel.

#36 Remove drivers side kick panel by pulling towards you, then remove the 10mm bolt that is revealed.

#37 Pull the rubber seal away from the car on both the passenger and drivers side.

#38 Remove both the passenger and driver side pillar trim.

#39 The dash is now ready to be removed. From the center pull with slight force. the dash will unclip and be loose. Make sure you have the dash completely loose.

#40 Once you are sure it's loose lean it forward a bit, then lift it over the steering wheel, and out the passenger side of the car.

Now it has taken me longer to write this that it did to remove the dash and put it back in!

Out: 1hr 17mins (taking pictures!)
In: in 42mins

Total: 2hrs


· Moderator
8,852 Posts
Here is a thread on how to disable a weak and theif-abused spot of stock security system.

· Moderator
8,852 Posts
In response to navigation options:
lisnup65 said:
Nav unit have come down in priice over the past year or so. One of the best bets out their for a simple all in one setup is the Pioneer Avic-N1. Its a complete stereo with flip out screen, DVD player, and Navigation built in. It is the most cost beneficial, but IMHO, not the most user intuitive device.
Now if you dont want to do a radio swap and just want navigation, then you have a few choices.
You can get a Pioneer, or Kenwood unit and a screen to accompany. These are units that are made to be mounted in the car, hardwired, and work really well. The next choice is portable unit which can be divided into 2 groups. The consumer group and the make your own group. The consumer group is units from Delphi, Garmin, etc. These are compact to semi-compact units that require only a cigarette lighter/accy connection. They normall dash or windshield mount and contain software built in. You may need to load maps per the area you plan to travel, but you get the computer cable and map discs with the unit. These units work and they work well, but they are slower, have longer load times, and are usaually not as user friendly as the mounted ones.
The make your own group is a multi-task machine. You can use either a lap top computer(I think this way is a joke as a laptop is just to big and they run way to hot), or a palm style hand held system. You get a GPS receiver antenna, and software. You can look for deals at like DELL for the handhelds and numerous websites offer the GPS antenna and software. You can build a hand held palm style navigation unit for around $400.00 if you do your homework. Not only will you get mobile navigation, but also all of the other features of the devive like MP3, and video playback, scheduler, and phonebook. I feel this is the most versatile and smart device as you can go car to car, use it walking down the street, etc. It does not seemlessly integrate into a car though as you can tell by the vent mount its not made for the car.

You can go from mild to wild, but your needs as well as budget need to be addressed. You can be looking at $300.00 tp $5000.00 fo a system. I myself have a installed system(Kenwood) in 1 vehicle as well as a made portable system for the other vehicles(I borrow this one out often).

Hope this helps you in your quest a bit.

· Moderator
8,852 Posts
GOIN4THE9S said:
We replaced the stock head unit and added 2 2ch amps to an 01 IS300 with navigation. We have removed the factory amp from the vehicle. Our problem is the navigation no longer works, the screen pops up and says Lexus but then goes blank and the screen starts tweaking out after a few minutes. Any ideas? Does the factory amp or factory dk need to be relocated in the vehicle?
Hello and welcome.
In order for stock navigation to function, stock amp MUST BE PRESENT. Also, one of the stock headunit boards MUST BE interfaced with stock amp for it to work.

Here are detailed instructions for aftermarket headunit installation, including stock navigation issues.

There is a member in UK that had success running stock nav with a presense of stock amp and a custom module desinged by him without relocating stock headunit PCB. That is the only known instance of making stock nav function without stock headunit. His name is omitted due to commercial nature of his "invention".

· Moderator
8,852 Posts
Selecting Wire Gauge taken from Crutchfield advisor site.
Cable Gauge Selection Chart
To determine the approximate current draw (in amperes) of your amplifier (or amplifiers), you must calculate first the total power of each amp (multiply the number of channels by the number of RMS watts per channel).

  • If you have multiple amps, add up the total power figures to arrive at a grand total.
  • Next, double your grand total power figure.
  • Then, divide by 13.8.
  • The resulting figure is your system's approximate current draw.

Compare this number to the numbers in the "Amperes" column in the chart below. Cross-reference with the cable length (the distance from your battery to the amp mounting location) to determine which gauge of cable you need.

Once you have estimated the total amperage of your system using the described formula, determine the proper power and ground wire gauge from this chart based on the length of power cable your installation requires.

Plan ahead. If you're going to add another amp in the future, you may want to take it into consideration when doing calculations. This way you won't have to run wires again when the time comes.
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