Aux Hack Test Points

[Adam Evans]

I was reading up on t'internet about the AUX Hack and the most promising post I have come across is this one

http://www.clublexus.com/forums/ls400/678054-95-ls400-nakamichi-aux-in.html

Is there anything like these test points in the Nav unit if so could someone please upload some photos as to their whereabouts as I would love this as an extra but dont quite fancy losing the use of the CD changer

Thanks in advance peeps

[ambermarine]

As I have said before on the subject of adding aftermarket electronics to the systems on the LS400, do so at your peril.The system in the pre 97 is different to the Sat/nav version and the incorporation of a display screen makes it less desirable to mess with .These units complete are 6K new and as rare as rocking horse s---t second hand.It is highly unlikely that anyone on the UK forum as been foolish enough to play around in there .I believe in keeping the car in its original state for all the right reasons.

[Cotswold Pete]

I would guess looking at the pictures on the link that the Nak board that the board has other circuitry missing due to an AUX port need a matching protected input and associated switching services from input to output.

I would suspect the extra control chips/components may also be missing - but only a guess.

Personally i would not go near and agree that keeping the car as original will be best and just use the Cassette player as AUX in with an adaptor, the sound is as good as you'll get any other way

The problem is that the head unit display will need re-programming to offer whatever an Aux In needs, and making sure the things like the Traffic report system can interrupt the circuit bus for the AUX input.

So if you are still going for it, you would need to access schematics for the display control and service control chip on the board.

By the way I am sure there are others more electronically up to date than me, been 15 years since I did any fiddling on any sort of PCB.

[ambermarine]

Cotswold Pete

You may not have messed with electronics for 15 years but you gave a comprehensive summary of all the reasons we don't mess in there ,nice summary.

[munday]

You're much better doing this: http://www.clublexus.com/forums/lexus-audio-video-security-and-electronics/269156-how-to-build-and-hardwire-an-auxillary-input-to-oem-stereo.html

I have done the above and used a Iphone cable that also has the charging wires built in.

A switch allows me to choose CD changer or Iphone output. You could use any plug instead of an Iphone one so its not apple specific :)

The advantages are that its neat, easy, gives the best sound quality you could possible expect (the normal headphone jack output is not as high quality as the line out signal that comes from the Iphone plug) and is cheap :)

EDIT: Also means that I can use the google maps Sat Nav, watch youtube videos, etc etc on either my phone or iPad and still have them charging.

[Adam Evans]

I have found this

http://www.clublexus.com/forums/gs-second-generation/657533-diy-simple-easy-no-fuss-aux-input-for-factory-headunit.html

This looks VERY interesting however has anyone got the schematics for the mk4 ls400 with Nav. I know an electronics whizzkid who may be able to sort this for me.

If I have the schematics it will be a lot easier

[Cotswold Pete]

You're much better doing this: http://www.clublexus.com/forums/lexus-audio-video-security-and-electronics/269156-how-to-build-and-hardwire-an-auxillary-input-to-oem-stereo.html

I have done the above and used a iPhone cable that also has the charging wires built in.

A switch allows me to choose CD changer or iPhone output. You could use any plug instead of an iPhone one so its not apple specific :)

The advantages are that its neat, easy, gives the best sound quality you could possible expect (the normal headphone jack output is not as high quality as the line out signal that comes from the iPhone plug) and is cheap :)

EDIT: Also means that I can use the google maps Sat Nav, watch youtube videos, etc etc on either my phone or iPad and still have them charging.

Does your method still allow the Traffic reports to interrupt.

[Adam Evans]

I think I have sussed it

Firstly

Here is the FULL service manual

http://elektrotanya.com/pioneer_lexus_ls400_kex-m9376_m9276-crt2064-.pdf/download.html

free to download

Next:

I know very little about this sort of electronics but from reading
numerous posts what you have to do is to interupt the L and R signal
from the tuner. As the signal is still in its raw form it has not been through the volume controll or the EQ or anywhere else yet

It is purely just a signal in a copper wire

It took me a good hour of looking at the board to finally find it

Simply just intercept the signal from the tuner and hey presto

No need for blank CD or anything just leave the radio how it is and then just plug in with your AUX and it will automatically switch off and divert the signal to your external music device as I have bought a switchable aux plug from maplin http://www.maplin.co.uk/pcb-mounted-3.5mm-stereo-socket-1196

No relays needed just 5 short lengths of wire and that plug

HOPEFULLY !!!!

I will be attempting this in the morning so I will update as the day goes on but I am fairly confident that this will work

[Adam Evans]

[Adam Evans]

EDIT:

After reading this http://forums.clubrsx.com/showthread.php?t=547118

I am 99% confident it will work

No more modulators, transmitters or blank discs !!!!!

Only dilema I have is where to but the AUX jack. Do I put it on the face of the stereo or do I hide it ??

[munday]

You're much better doing this: http://www.clublexus.com/forums/lexus-audio-video-security-and-electronics/269156-how-to-build-and-hardwire-an-auxillary-input-to-oem-stereo.html

I have done the above and used a iPhone cable that also has the charging wires built in.

A switch allows me to choose CD changer or iPhone output. You could use any plug instead of an iPhone one so its not apple specific :)

The advantages are that its neat, easy, gives the best sound quality you could possible expect (the normal headphone jack output is not as high quality as the line out signal that comes from the iPhone plug) and is cheap :)

EDIT: Also means that I can use the google maps Sat Nav, watch youtube videos, etc etc on either my phone or iPad and still have them charging.

Does your method still allow the Traffic reports to interrupt.

Not if you are currently listening to the ipod, I have mine switched off anyway (when going somewhere I dont know, google maps is always used which has live traffic info).

If you are listening to a CD/radio/tape as you usually would then all the stock functionality is maintained.

The method of stripping down the headunit is a lot more involved! You also still only have the headphone out, which is LOWER QUALITY (why taint the excellent sound system with poor quality audio?!) and you also don't have the opportunity to add in a power source to charge your phone/music player.

Whatever floats your boat, I know that my install is one of the best and most complete ;)