DIY Nakamichi Head Unit 3.5mm (Aux) Install '98-02 (1 Viewer)

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DIY Factory Nakamichi Head Unit 3.5mm Aux Install '98-02 (I think this is the same unit through 2002 but could be wrong).

I really enjoy the factory look of my head unit in my '99 LX470 but have been frustrated by the low sound quality of my $2 FM radio adapter.
I decided to figure out a way to install a stereo 3.5mm (AKA Auxiliary cable) input bypassing the over-the-air waves.

I found a company in California who will do this for $60 plus shipping (which I am sure is expensive right now). I know we mudders can do better :grinpimp:
I might consider doing this for others if interested. PM me and we can work it out.

This mod uses the AM radio input contacts, bypassing the radio. This means that when a device is plugged in, playing music, and the unit is on the AM radio function, the user's audio from the 3.5mm cable takes precedence. When unplugged, the radio reverts back to AM audio. Both systems operate harmoniously and can therefore be used to full functionality.

I will post pictures and steps in the thread below.

20210415_205919.jpg

I removed the side brackets from the unit so that it would rest easily on the bench. Not required but if you want to, Phillips head sriver or 8mm socket

(Skip to step three (3) if you know how to remove the head unit and/or trim facia)

Tools/materials I found useful and/or are required:

Flathead(s)
Phillips Head Driver(s)
Wire cutters/crimpers/strippers
22-18 AWG wire - I chose a very firm wire so that I could mold it to fit the shape I wanted for the install (three colours is cool but unnecessary)
Heatshrink (varying sizes)
Heat gun or hairdryer (not pictured)
Soldering iron or gun (not pictured)
Alligator clips and/or magic arm (not owned, ergo not pictured)
3.5mm stereo (three distinct bands) female or male jack (I chose female, the male pictured is leftover from the job)
One (1) small crimp connector, screw type (red is close size for 22-18 guage wire)
20210415_210121.jpg


1. Remove wood grain or other center facia trim -
I don't have pictures for this because it has been covered more times than an old plaster wall. That said, use trim removal tools or if you like, a flathead screwdriver (be careful not to scuff the dash). There are four points of secuirty on the sides of the trim (2 each side).


2. Remove radio -
Once the trim is out of the way, remove the radio using a Phillips head screwdriver (4x screws).

Once the screws are out, pull the unit away from the dash and disconnect the singular harness from the unit. There are also two (2) antenna cables that plug into the back of the unit. Remove these.


3. Void Warranties -
Cut the yellow seal tapes if they have not already been cut away. Mine had been "remanufactured" (the CD player was removed to prevent ER3 or whatever the famous error was) so the seals were already broken.

For this mod one must only extract two (2) screws from the unit. On the back of the unit the farthest left screw and the second screw from the right must be removed in order to open the top panel.
A nice large tip driver is best for these screws. Some significant pressure may be required.
20210415_205834.jpg


4. Remove top panel -
Pry up on the top panel to remove it. Be gentle but don't be afraid to use a bit of muscle. I think I used a flathead to pry it open the first time.
20210415_205434.jpg


The wires protruding from the back are not factory. We will get there. I stupidly took photos after the job was done.
Continued in next post...
 
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Post Two (2)

5. Locate contacts for soldering. They are designated L and R (left and right). They are close to one of the ground screws and not far from where the ribbon cable on the tape deck plugs in.

You can see in the pictures where I wired them. bLack is Left, Red is Right

20210415_205458.jpg


A closer look:

20210415_205453.jpg


20210415_134150.jpg

At this point, many readers will know where to go, but I'll include more details for the sake of documentation and interest.

Continued in next post
 
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6. Connect stuff -
Solder the wires to the contacts making sure not to contaminate the contacts or create a short. I applied some extra solder to the contacts in an effort to prepare them to receive the wire. I found that pre-bending the wires was useful in getting them to sit still where I wanted.

7. Clean it up -
I bent the wires so that they would rest over top the female harness connector. When the metal top plate of the unit is put back it will hold them all in place.

I heat shrank (that's a verb, right?) the left and right wires together for durability/to mitigate stress on the contacts. I then heat shrunk (grammar?) all three (L, R, GND) in one bundle from there.

At this point one will have three wires protruding from the rear of the head unit. In the next step, the audio jack will be connected to the unit. If you wanted, you could skip the wires and just solder the 3.5mm cable directly to the contacts but I did not feel that this would be a robust option. Personal preference I suppose.

20210415_205523.jpg

Wires

20210415_205511.jpg

Side mount brackets (I removed these so the unit sat flat on the table)
 
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8. Connect 3.5mm Jack -
Finally, solder the three wires from the aux cable to the wires now installed on the head unit. There are many brands and variations of cable, etc so the colour schemes will undoubtedly be different but the general standard is Right Red, Left bLue, Green Ground.

My apologies for the low quality pictures but in an effort to correct this, I also included a helpful wiring diagram from a male 3.5mm cable end.

20210415_205610.jpg

Red, Green, Blue (Right, Ground, Left, respectively)

20210415_205641.jpg

Male and female

57c69af622a757d2b814762f8335f518.jpg

In this example it appears that R is red or orange and that L is yellow (white for ground)

I then used heat shrink on the connection points to secure and protect them. This is by far and away the ugliest part of my handiwork. I will clean it up later. That looks terrible.
20210415_205557.jpg
 
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And just like that you have added a 3.5mm audio input to your factory head unit for the low cost of free to ~ $5. Not bad.

To use the new install, set your radio to AM while the jack is plugged in and audio is playing over the cable. To use the AM radio, unplug the jack from your phone.

The input this mod splices into is, surprise, for the AM radio but it does NOT play music over the air meaning no more squealing or searching for a station without static.

I would love to see others' attempts (and hopefully successes) at this mod as I am uncertain if many have done this.

If you're interested enough in more mods and things I do, I have an instagram account for the truck @patch_lx470


EDIT: I forgot to mention, where you route the newly installed jack is up to you. I am going to route it into the center console or into the ashtray. I have not yet decided which.
 
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I did this mod today. Thanks for the write up! I've wanted to do it for a long time but didn't know the solder points.

I'll probably pick up a 12v bluetooth receiver and wire that in behind the dash. I took out an aftermarket double din that had been giving me problems. I pretty much only used the bluetooth function, so this is perfect for me.

Note to others... My 98 is not Nakamichi, but looks identical to the Nak headunit minus the logo. Happy to report it looks identical inside too.
 
Joined
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Messages
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I did this mod today. Thanks for the write up! I've wanted to do it for a long time but didn't know the solder points.

I'll probably pick up a 12v bluetooth receiver and wire that in behind the dash. I took out an aftermarket double din that had been giving me problems. I pretty much only used the bluetooth function, so this is perfect for me.

Note to others... My 98 is not Nakamichi, but looks identical to the Nak headunit minus the logo. Happy to report it looks identical inside too.
I'm so glad someone else could use this! By any chance do you have any photos? I'd love to see it, especially after you install the Bluetooth receiver.
 
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I'm looking at something like this.

There are other options (this would be easy to throw in the center console assuming you run the aux input there), but there are issues with almost all of the 'car' bluetooth receivers, namely that they usually want to be a hands-free phone audio device, so that when you get a call it wants to connect. They also beep a lot when powering on and just sort of suck in my experience.

For a while I'm going to run with the aux cable though. This is the best I've heard my system since I got the truck.
 
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One thing I don't love is the antenna being powered (and thus raised) when on AM.

Anyone know a trick to get it to stay all the way down? The problem would be the occasional times I want to listen to an FM station, my antenna would be down. I'll probably have to live with it up, but I'll hear ideas if anyone has any.

I wonder if tape or CD input points exist? My in-dash CD changer doesn't work anyway.
 
Joined
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Messages
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Location
Atlanta, Georgia
One thing I don't love is the antenna being powered (and thus raised) when on AM.

Anyone know a trick to get it to stay all the way down? The problem would be the occasional times I want to listen to an FM station, my antenna would be down. I'll probably have to live with it up, but I'll hear ideas if anyone has any.

I wonder if tape or CD input points exist? My in-dash CD changer doesn't work anyway.
I am finding the same thing. My solution is probably going to be to install a kill switch in the antenna motor wiring. That way I can turn it on when I need radio and off when I'm using the AM input.

I looked for other input solder points but couldn't find one. If you do find anything please share.
 
Joined
Nov 24, 2020
Messages
29
Location
Atlanta, Georgia
And just like that you have added a 3.5mm audio input to your factory head unit for the low cost of free to ~ $5. Not bad.

To use the new install, set your radio to AM while the jack is plugged in and audio is playing over the cable. To use the AM radio, unplug the jack from your phone.

The input this mod splices into is, surprise, for the AM radio but it does NOT play music over the air meaning no more squealing or searching for a station without static.

I would love to see others' attempts (and hopefully successes) at this mod as I am uncertain if many have done this.

If you're interested enough in more mods and things I do, I have an instagram account for the truck @patch_lx470


EDIT: I forgot to mention, where you route the newly installed jack is up to you. I am going to route it into the center console or into the ashtray. I have not yet decided which.
Update: I installed the cable through to the ashtray. I drilled a hole through the back of it as any good cruiserhead would do.

20210419_191621.jpg
 

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