Sanity Check on Head Unit Upgrade (1 Viewer)

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Hello 100 series hive mind, I've read the threads, everyone has done a lot of great work doing research, and before I open up my center stack, I am hoping for a quick gut check from you folks.

2000 LX470, Nakamichi in dash changer, wanting to install a double din Android Auto head unit. Here is what I think I know:

  1. The head unit can be hard wired into the factory harness if you have the necessary mechanical skills to do so and the appropriate wiring diagrams.
  2. The amp can be bypassed if you have the necessary mechanical skills to do so and the appropriate wiring diagrams.
  3. Bypassing the factory amp works because the head unit standard has more amplification than the stock head unit+amp
  4. There is no off the shelf wire adapter that can be purchased for this particular setup (though it can be fabbed from two OEM Toyota connectors).
It seems like there are two camps that do the work, people that are terrified of it and people to which it is not a big deal. I've rebuilt engines, motorcycle and dirtbike suspension, married wire looms from 80's Toyotas to 90's engines, I know a thing or two, but with what seems like such polarity in outcomes, I am wondering if there are some gotchas that I'm not seeing. It appears on the surface to be quite straightforward but I also know that late 90's/early 2000's luxobarges were ripe with piggybacking systems that can get very upset if you mess with them.

It's a dumb question guys, but tell me I'm not crazy, putting a new head unit in this barge isn't a big deal, is it?
 
I preferred building the harness to butchering the factory harness.

I found the install to be fairly trivial, but I’ve been doing my own stereo installs since I was a teen.

I didn’t try one of the Android head units, because I had mixed results with them in my son’s 00 LC. A Sony CarPlay unit has met my needs.

No, not a big deal, on a non-nav 100.
 
Step 1. Call Crutchfield
Step 2. Order Double Din of choice
Step 3. Order their ready harness service for $24 -- Basically looking a plug and play for install.
Step 4. Install head unit in about an hour.

With the ready harness it is basically a one banana job. You'll spend more time figuring out which RCA jack goes to which speaker output on the head unit than anything else.
 
Step 3. Order their ready harness service for $24 -- Basically looking a plug and play for install.
On a Nakamichi LX:
1677617156753.gif


(I was not able to find an aftermarket adapter for the early LX470 harness, from the usual suspects)
 
On a Nakamichi LX:
View attachment 3260861

(I was not able to find an aftermarket adapter for the early LX470 harness, from the usual suspects)

Yep, that's what I found. Normally that's my go to to verify installation needs. Crutchfield says:

1677619479023.png



Whomp.

Not that it's the end all be all of information, but it isn't as easy as a non-Naki unit, of which I do know there is an adapter harness!
 
IMG_1113.JPG

This is Nak harness bypass without speaker injunction under the seat (those colors can be matches and ID'd in door). I ran RCAs from head unit to under seat and used new speaker wire from aftermarket amps to doors due to power demands. Got the plastic harness clip from Corsa. There is a thread about it somewhere on here. But these are the power, ground, switch, and antenna to OEM harness in order to avoid cutting it. Allows unit to turn on and shut off via ignition. Its super close to Metra's 70-1761 toyota harness. May need to switch around Power and switch. I hope this helps the Nakamichi crowd.
 
I think people get worked up about it because there are so many different options that it's hard to know what you'll be getting into until you start. And there's a lot of conflicting information out there.

Then there's the whole double feedback loop in the amp so that has to be bypassed. Overall not hard, but confusing.
 
My last LX had a Nak system and I wired my own adapter with no problem. Didn't even need to bypass the amp. It was truly plug and play once I was done pinning.

Theres a great how-to here: Nakamichi Update - '99 LX 470 - https://forum.ih8mud.com/threads/nakamichi-update-99-lx-470.1066006/#post-11738419

I still have an unused connector and pins to build a Nakamichi adapter if you choose to take this route, I'm happy to send them off for cheap. My new LX has a Mark Levinson system which is its own headache.
 
I think people get worked up about it because there are so many different options that it's hard to know what you'll be getting into until you start. And there's a lot of conflicting information out there.

Then there's the whole double feedback loop in the amp so that has to be bypassed. Overall not hard, but confusing.
This...

I'd much rather take on a timing belt job over installing a new head unit. I need to get around to replacing mine, but I'm suffering from analysis paralysis. (and some intimidation) There seems to be no clear go-by's and no clear list of exactly what you need to buy. The info is mostly out there, but it's fragmented across multi locations.
 
My $0.02 having done option 1 on my 99 LX with Nakamichi.

There are two main avenues you can go down here:

1. Build harness adapter using Toyota connector or splice directly into factory wiring, retain Nakamichi amp, swap head unit. Very easy and straightforward.
2. Replace head unit and bypass Nakamichi amp, more involved, likely not difficult with the right diagrams and knowledge, but will take more time.

I went with option 1, I didn't need a crazy amazing sound system, I just wanted Car Play and modern functionality. Plus, as they all do, the original Nakamichi 6 disc changer was malfunctioning. If you're apprehensive about this project and aren't looking for earth shaking sound, why not start with option 1? That will easily modernize the truck and get you a good functioning system. At that point, if you're still not happy with the sound, you can move on to amp bypass, speaker replacement, or whatever level you want to pursue.
 
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I appreciate everyone's help with this on this thread and other threads on the board.

Finally getting to this project, and after the headunit install, all works fine, but there is a consistent static/pop from the speakers. I am retaining the factory Naka amp, and the sound is actually quite good, but there is some sort of feedback in the system that I can't identify. The static is completely independent of the volume selection, it is a constant volume.

I am guessing there is something in the Amp turn on signal that is causing an issue. The headunit I purchased did not have a specific Remote on signal, so I've experimented with the power antenna signal, or 12+ from ignition with no change to the result.

I'm not particularly interested in bypassing the amp, as the sound quality is adequate, besides the static. I'm wondering if there is a cleaner way to turn on the amp, or if there could be possibly something wrong with my HU?

Any suggestions?
 
That static is likely ground loop from having kept the stock amp. I highly suggest bypassing it, as I did everything under the sun and just couldn't get rid of it. All of the symptoms similar to yours. Eventually just did a bit of snipping and crimping and it was right as rain.
20230430_083859.jpg


Edit- I see you're not interested in bypassing the amp, and neither was I, but I couldnt live with the static and the amp bypass took an hour to accomplish and nailed the problem easily.
 
That static is likely ground loop from having kept the stock amp. I highly suggest bypassing it, as I did everything under the sun and just couldn't get rid of it. All of the symptoms similar to yours. Eventually just did a bit of snipping and crimping and it was right as rain. View attachment 3324969

Edit- I see you're not interested in bypassing the amp, and neither was I, but I couldnt live with the static and the amp bypass took an hour to accomplish and nailed the problem easily.

Thanks, yea, I think that's the route I'll need to go with.

Can I ask high level how you went about it? Did you run the speaker wires from the HU down to the amp? Or were you able to do all of the work down by the amp itself?
 
If you do not have a wiring schematic you can pull the door panels and see the colors coming from each speaker. Match each color to corresponding colors by the amp under the seat. Then you will know each individual speaker color at the head unit and so on. You can use speaker wire from the head unit harness you created to corresponding color wire at the amp and you have successfully bypassed the amp. It is 8 wires (2 per speaker). Heads up: Sub will be lost unless you have a small amp to run it. I would recommend Alpine power packs or JL audio micro amps (4 channel for everything else and/or mono for sub). They can be hidden in dash or in OEM amp location. The static is back feeding power interference from OEM amplifier interference. You can try a ground loop isolator and wrapping power wires with Tessa tape. Ground loop isolators are cheap maybe less than $5 a piece. But are mostly a bandaid. It will happen again with OEM amp. Most of the time it's the 12V power from power antenna motor and audio amplifier jumping the soy based factory wire jacket and regular vibration from contact that you hear. Hope this is helpful.
 
Thanks, yea, I think that's the route I'll need to go with.

Can I ask high level how you went about it? Did you run the speaker wires from the HU down to the amp? Or were you able to do all of the work down by the amp itself?
I did all the work down by the amp itself. Checkout the stereo FAQ, I dropped full instructions there to make it super easy.
 
If you do not have a wiring schematic you can pull the door panels and see the colors coming from each speaker. Match each color to corresponding colors by the amp under the seat. Then you will know each individual speaker color at the head unit and so on. You can use speaker wire from the head unit harness you created to corresponding color wire at the amp and you have successfully bypassed the amp. It is 8 wires (2 per speaker). Heads up: Sub will be lost unless you have a small amp to run it. I would recommend Alpine power packs or JL audio micro amps (4 channel for everything else and/or mono for sub). They can be hidden in dash or in OEM amp location. The static is back feeding power interference from OEM amplifier interference. You can try a ground loop isolator and wrapping power wires with Tessa tape. Ground loop isolators are cheap maybe less than $5 a piece. But are mostly a bandaid. It will happen again with OEM amp. Most of the time it's the 12V power from power antenna motor and audio amplifier jumping the soy based factory wire jacket and regular vibration from contact that you hear. Hope this is helpful.
No need to check speaker wiring, amp wiring colors match harness. Plenty of info in the stereo FAQ and elsewhere on what's what.

Also, the factory sub is kinda s***. I dropped $100 on a powered sub on Amazon and stuck it in the factory amp location. Money well spent IMHO.
 
Last edited:
My $0.02 having done option 1 on my 99 LX with Nakamichi.

There are two main avenues you can go down here:

1. Build harness adapter using Toyota connector or splice directly into factory wiring, retain Nakamichi amp, swap head unit. Very easy and straightforward.
2. Replace head unit and bypass Nakamichi amp, more involved, likely not difficult with the right diagrams and knowledge, but will take more time.

I went with option 1, I didn't need a crazy amazing sound system, I just wanted Car Play and modern functionality. Plus, as they all do, the original Nakamichi 6 disc changer was malfunctioning. If you're apprehensive about this project and aren't looking for earth shaking sound, why not start with option 1? That will easily modernize the truck and get you a good functioning system. At that point, if you're still not happy with the sound, you can move on to amp bypass, speaker replacement, or whatever level you want to pursue.

For me, option 1 resulted in sound quality similar to a walkie talkie.

I appreciate everyone's help with this on this thread and other threads on the board.

Finally getting to this project, and after the headunit install, all works fine, but there is a consistent static/pop from the speakers. I am retaining the factory Naka amp, and the sound is actually quite good, but there is some sort of feedback in the system that I can't identify. The static is completely independent of the volume selection, it is a constant volume.

I am guessing there is something in the Amp turn on signal that is causing an issue. The headunit I purchased did not have a specific Remote on signal, so I've experimented with the power antenna signal, or 12+ from ignition with no change to the result.

I'm not particularly interested in bypassing the amp, as the sound quality is adequate, besides the static. I'm wondering if there is a cleaner way to turn on the amp, or if there could be possibly something wrong with my HU?

Any suggestions?

It's a floating ground which conflicts with the aftermarket unit's battery ground. The two differing grounds must be unified and you cannot do that while attempting to use the factory amp. It's not possible and must be bypassed.

Thanks, yea, I think that's the route I'll need to go with.

Can I ask high level how you went about it? Did you run the speaker wires from the HU down to the amp? Or were you able to do all of the work down by the amp itself?

I've got a Youtube video on it for the 99LC, but the process is the same for all 100, far as I know. Different wire arrangements, but the same concept.

1. Run speaker wires from aftermarket unit to the speaker wires coming out of the factory amp. Splice together. I prefer to pin new connectors, but you can just hack up the wiring if you choose.
2. Keep power leads (battery and ignition, I think?) connected so that the dash head unit has power. The factory head unit power comes from the amp. You need to maintain this power.




There is no fix for floating grounds in the 100 that results in anything resembling acceptable sound quality, IMO. Maybe there's some wiring configuration out there that keeps the chassis and OEM floating ground very, very close, but I haven't seen it. When I tested with a DMM, voltage was all over.

Ancient video here, but perhaps helpful.
 
I did all the work down by the amp itself. Checkout the stereo FAQ, I dropped full instructions there to make it super easy.

Happen to have a link? I'm okay with running wiring from the HU down to the amp to pick up the speaker wiring, but I have to imagine I could bypass it down there, just cannot seem to find a diagram that shows the inbound speaker wiring.
 
I did option 1 with my 99 LX with Nakamichi. I spliced the factory wiring and just matched the wires from the diagrams posted on mud. There is static in the speakers when the headunit powers on and the Pioneer logo appears at first but it disappears once the amp comes on (usually within 1 second and the logo is still displayed).

No issues in three years and the sound from the Nakamichi is actually decent with the aftermarket head unit. Not sure why others are having problems. Maybe poor wiring connectors.
 

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