Lexus IS Forum banner

1 - 17 of 17 Posts

·
Registered
Joined
·
10 Posts
Discussion Starter #1
:confused:

I know this has been asked before here... I searched a lot and saw many different posts.. but i want to try my luck...

has anyone SUCCESSFULLY, AFFORDABLY installed an aftermarket HU on a Lexus IS 300?

i know the IS300 has a factory amp that causes all the problems..

if anyone can let me know what to do, i would appreciate it..

i have a new radio and install kit.. i just dont know what harness to get or how to go about doing this...

thanks in advance.. :confused: :confused:
 

·
Registered
Joined
·
4,742 Posts
I was about to post about the same thing. How easy is it to install a new one? Could joe smoe do it or do you need to take it to a place where they know what there doing?

If it changes anything im talking like a Eclipse AVN5435
 

·
Registered
Joined
·
23,822 Posts
Its easy, and very affordable.

You bypass the stock amplifier and extend the wires on the output side of the amplifier to the output side (the wires coming out) of your head unit.

I think you have to figure out a few wire colors here and there, but this is a very easy thing to do. If you have any knowledge at all with car electronics (meaning you can turn a stereo on without wondering which button it is) you should be able to do this.
 

·
Moderator
Joined
·
8,880 Posts
There's an upgrade diagram for just such occasion located in the useful posts sticky. No working wire harness is available.
 

·
Registered
Joined
·
10 Posts
Discussion Starter #5
someone mentioned that you need the SOUNDGATE XR4... can this be used?
http://www.audiooutfitter.com/store/XR4.html

or a Scosche TA03??
http://www.sounddomain.com/sku/SCOTA03B

do i need to replace all my speakers as well or just rear or what?

are there any steps on how to do this that i can follow?

im sure its not so difficult to do.. but if you dont know what to do, its difficult trying to figure it out what to do..

magoo, you confused me.. you said i bypass the stock amp, and then extend the wires on the output side of the amp to the output side of the HU..

so extend what wires on to the output side of what amp?? the stock amp i bypassed????

can you please give some details.. i am good with electronics.. i can install it myself.. i just need to know what needs to be done exactly.. i spent a lot of $$, and dont want to spend much more...

thanks
 

·
Registered
Joined
·
23,822 Posts
Ok basically you have 8 wires coming out from your aftermarket head unit that are to be wired to the speakers (FR+/- FL+/- RR+/- RL+/-).

From the stock amplifier, there is a number of wires (I'm not sure) leading from the stock head unit to the amplifier. Those carry a digital signal. The output from the stock amplifier is in the form of 8 wires (I believe, please correct me if I'm wrong vlad). You need to take those wires and connect them to the 8 other wires coming from the aftermarket deck.

There are a few other wires that need to be connected to the aftermarket head unit, but there are plenty of threads that provide that information.

Basically, you can't use all of the stock wiring like in most cars. Think of it as an extension cord that is needed. The output side of the stock amplifier leads to those 8 wires, and you need extension cords to connect those to the aftermarket head unit wire leads.
 

·
Registered
Joined
·
820 Posts
You take the speaker outputs of your aftermarket HU and extend them to the passanger-side kickpanel, where the stock amp is located. Then you take the speaker wires located in the output side of the stock amp and cut them. After you've done that, connect the wires from the aftermarket HU you just extended and solder, crimp, [whatever floats your boat], to the speaker wires you just cut.
 
  • Like
Reactions: magoo

·
Registered
Joined
·
820 Posts

·
Registered
Joined
·
23,822 Posts
aemjr said:
You take the speaker outputs of your aftermarket HU and extend them to the passanger-side kickpanel, where the stock amp is located. Then you take the speaker wires located in the output side of the stock amp and cut them. After you've done that, connect the wires from the aftermarket HU you just extended and solder, crimp, [whatever floats your boat], to the speaker wires you just cut.
Wow. I overexplained it. Thank you, +rep.
 

·
Registered
Joined
·
820 Posts
hahaha thnx! :cool:
 

·
Registered
Joined
·
10 Posts
Discussion Starter #11
thanx guys!

there are 2 wires coming from the stock amp to the stock HU.

ok so basically i do not even use these factory harnesses shown below.. i just extend the aftermarket hu wires to the output wires of the stock amp manually..

what type of wiring do i need to buy to extend this? what gauge?

is there labeling on the output wires of the stock amp, so i know what hu wire to connect where? if not, any simple way to figure it out?

will i need new speakers?
 

Attachments

·
Registered
Joined
·
1,104 Posts
everything is color coded, not labeled. if you do some searching you should be able to find some wiring diagrams.

if i remember correctly i used 18 gauge wire, but i only have the front stock speakers hooked up.
 

·
Useless
Joined
·
5,346 Posts
mujtba said:
thanx guys!

there are 2 wires coming from the stock amp to the stock HU.

ok so basically i do not even use these factory harnesses shown below.. i just extend the aftermarket hu wires to the output wires of the stock amp manually..

what type of wiring do i need to buy to extend this? what gauge?

is there labeling on the output wires of the stock amp, so i know what hu wire to connect where? if not, any simple way to figure it out?

will i need new speakers?
Please check the sticky for wire color info.
You can get 12V+ (Blue/yellow), Acc(Gray), Ground(Brown), antenna(Black) at the harnesses you have posted pics of.

You will need to run speaker wire(I recommend 16 awg as min) to the amp location.

I will look for the colors, but I do not remember off the top of my head. You must unplug the harness from the amp before making connections if you T solder them. If you cut it then all is good.

Front speakers can stay and will work fine.

Rear speakers are an issue. You actually have 2 speakers in each location in the rear deck. The mids and a 6*9 woofer. Because the factory amp seperated the signal and provided cross-overs inside I recommend changing them out for full sound.

Others will tell you that their great installer got them to work right, but DO NOT listen as they are BS'ing you. The only way to get the speakers to work right is to hand build a passive X-over. Most installers today do not know how to build these as systems are sorta packaged now.

By not using the X-over, you have your choice of connecting just the woofer or just the mid. The woofer is 2 ohms and deck dependant would indicate if it can handle it as the built in amps on these units are WEAK!. If it does work, you will only have the lower octaves from the 6*9 as their is no cone or mid section built in.

If you connect just the mid section, then you better add a sub to the setup as the 6*9's are what creates the little bass in the factory system. The mids will require at least a cap to create a 6db x-over as they will NOT handle the low freqs sent to them by a full range signal such as an aftermarket headunit. These are relatively cheap.

If you want to try your hand at using both the 6*9 and the mid, then series the connection for a 6 ohm load. You will still need the cap on the mids. The issue here is that the amp will produce less power to the speakers which results in a even worse performance than the stock setup.

I hope this has helped answer this DAMN ? again! (No offense to you, but this has been asked at least 1500 times in the past 4ish years.)
 

·
Registered
Joined
·
10 Posts
Discussion Starter #14
thanks!

what do you mean by "You can get 12V+ (Blue/yellow), Acc(Gray), Ground(Brown), antenna(Black) at the harnesses you have posted pics of."

Did you find the color codes? I saw a few, but dont know if I am looking at the right ones.

Also, if I replace the 6*9, can an aftermarket 6*9 fit into the slots?

Can I use the wiring already in place for the speakers?

++++++++
P.S: Also, I know this was asked many times before, but I think people will continue to ask this question since there is no straight forward answer to install an aftermarket radio with steps. Atleast a generic steps where theres no subs or anything involved would be helpful. If I successfully install mines, thanks to the help of people like you, I will write up some generic steps and see if they post it in the sticky.
++++++++

thanks again! :)
 

·
Useless
Joined
·
5,346 Posts
mujtba said:
thanks!

what do you mean by "You can get 12V+ (Blue/yellow), Acc(Gray), Ground(Brown), antenna(Black) at the harnesses you have posted pics of."

Did you find the color codes? I saw a few, but dont know if I am looking at the right ones.

Also, if I replace the 6*9, can an aftermarket 6*9 fit into the slots?

Can I use the wiring already in place for the speakers?

++++++++
P.S: Also, I know this was asked many times before, but I think people will continue to ask this question since there is no straight forward answer to install an aftermarket radio with steps. Atleast a generic steps where theres no subs or anything involved would be helpful. If I successfully install mines, thanks to the help of people like you, I will write up some generic steps and see if they post it in the sticky.
++++++++

thanks again! :)

Those are basic connections that your new head unit will require!

I have not had a chance to find my notes for wiring colors at the amp.

Most 6*9's will fit with very minor modifications.

You can cut and solder to the factory speakers wire if only running power from the headunit.(No big amp)

Off the top of my head for colors(Please NOTE that I am not responsable for an installer not verifying this information)

FL+ purple
FL- blue

FR+ Light Green
FR- light blue

RR+ woofer Red/white
RR- woofer White/Lightblue

LR+ woofer Black/white
LR- woofer Yellow/red

RR+ mid Red
RR- Mid White

LR+ mid Black
LR- mid Yellow
 

·
Registered
Joined
·
10 Posts
Discussion Starter #17
thanks again...

i took a look at my rear speakers from inside my trunk.. all i saw was one 6*9 on each side.. ( 2 total )

you said we have 2 speakers in each section, meaning 4 in the back.. ( 2 subs and 2 mids.. right ? )... so is my car different, or do these 6*9 speakers that I can see have 2 seperate speakers built inside them that cannot be seen from the bottom inside the trunk?

also, i looked in the back of the glove compartment for the amp.. is it the silver box on the right side? that seemed to be an amp..

anyhow, how do i get to those output wires from the stock amp? everything behind the glove compartment seems to be bolted down! aaahhh

--sigh--
 
1 - 17 of 17 Posts
Top