THX navigation to aftermarket

voyeur

Well-Known LVC Member
Joined
Apr 26, 2010
Messages
304
Reaction score
17
Location
Phoenix
Excellent write up. I like creating these kind of documents at work. Nice and clear document. I also am looking to replace my THX with a Alpine Car Play. Looking to hear how it works with the existing THX hardware. I have been without at least CD playback since my car was at the dealership last (no idea what they did). All I have is THX stereo playback for now.

Show some post installation pictures!
 

The Stevinator

LVC Member
Joined
Feb 24, 2015
Messages
10
Reaction score
2
Location
United States
Excellent write up. I like creating these kind of documents at work. Nice and clear document. I also am looking to replace my THX with a Alpine Car Play. Looking to hear how it works with the existing THX hardware. I have been without at least CD playback since my car was at the dealership last (no idea what they did). All I have is THX stereo playback for now.

Show some post installation pictures!

Will-do. I believe I get the silver metra kit in the mail today. I'm really glad Crutchfield provided the black one though. It made me feel much more comfortable modifying something I knew I could just throw away without much loss. I'll add some final install pics to the doc and post another revision once it's done. For now, I'm cruising with some of my interior panels still off (as I'm super paranoid about the plastic pieces breaking from pulling on/off). But it sounds great! It may just be my excitement of having a new toy, but I would swear it sounds better than the factory gear.
 

n8bachelor

Dedicated LVC Member
Joined
Dec 30, 2005
Messages
1,622
Reaction score
11
Location
Bentonville, AR
Does anyone know the voltage output of the factory head unit? I'm concerned that some aftermarket head units output 2v, some 4v, and some others for the RCA outputs. How will that affect the performance of the factory amps? Will any difference be made up by volume adjustments since we are not using the amp in the aftermarket head unit anyway?

I'm getting ready to replace my factory HU and want to consider the output voltage of the aftermarket RCAs in my purchase if that is important. I'd prefer choosing based on other options but want to consider it if it will be an issue.
 

1LoudLS

Dedicated LVC Member
Joined
Mar 31, 2008
Messages
9,895
Reaction score
356
Location
Ann Arbor
the higher the headunits pre output voltage, the lounge the subs play at the same volume setting. this is easily countered by turning the level down in the radio settings.

don't know what the OEM voltage output is, but just about every aftermarket radio seems stronger. and i usually have them turned down a bit to get the same balance as the factory radio.
 

joegr

Dedicated LVC Member
Joined
Dec 10, 2005
Messages
21,160
Reaction score
2,107
Location
Gulfport
Well, in this case it's not just the subs, it's all the speakers. The JVC I put in has 2.5V out levels. Those certainly aren't too high. My normal listening level is 16 to 20 on a volume knob scale that only goes to 40. (Of course, it's not linear, so that's not close to half of max volume.)
 

ChicoJW

New LVC Member
Joined
Dec 21, 2017
Messages
7
Reaction score
0
Location
Atlanta
This work is very valuable and considerate to others - Excellent! work and write-up. I have a 2006 Lincoln LS with THX and NAV and planning to replace radio and love the idea of not having to re-wire speaker cables and bypass the factory amp.
I do have one question if you can find the time to answer.
What is the 2.2 Ohm resistor for ? what is the purpose ? The reason I am asking is that I am planning to install one of the newer Kennwood Radios instead and want to make it work OK.
Thank you so much!.
 

joegr

Dedicated LVC Member
Joined
Dec 10, 2005
Messages
21,160
Reaction score
2,107
Location
Gulfport
...What is the 2.2 Ohm resistor for ? what is the purpose ? The reason I am asking is that I am planning to install one of the newer Kennwood Radios instead and want to make it work OK.
Thank you so much!.

It isn't 2.2 ohms. It is 2.2K ohms (2,200 ohms), a big difference. It's to keep the remote turn on signal for the amps from over-driving the turn-on input to the amps. Without it, there would be a pop when the amps turned on each time.
The factory amps actually have a diagnostic feature that can drive a signal out on that line when there is a problem. I have seen several recommend using a 5V regulator instead of the current limit resistor, but that is actually the wrong way to do it, since that doesn't allow for the amp to drive a signal back on that line. The current limit (2000 or so ohms) resistor does.
 

joegr

Dedicated LVC Member
Joined
Dec 10, 2005
Messages
21,160
Reaction score
2,107
Location
Gulfport
As a follow-up question. Is there ea specific reason not to use the following instead of the 2.2K other than cost ? would it have to be at lease 1W resistor ?
Axxess Interface AFDI-5V Ford 12V to 5V Step Down


Thank you

Um...

...The factory amps actually have a diagnostic feature that can drive a signal out on that line when there is a problem. I have seen several recommend using a 5V regulator instead of the current limit resistor, but that is actually the wrong way to do it, since that doesn't allow for the amp to drive a signal back on that line. The current limit (2000 or so ohms) resistor does.

A 1/4 watt resistor is fine. They cost about $0.01 from electronic suppliers. You would rather pay $12 instead, and stress the amp?
(Amazon rips you off at $6 for 10 of them. www.amazon.com/Projects-10EP5122K20-2-2k-Resistors-Pack/dp/B0185FKB2S/ref=sr_1_1_sspa?ie=UTF8&qid=1514426809&sr=8-1-spons&keywords=2.2K+resistor&psc=1)

That said, no one has reported damage using the 5V regulators. It just bugs me as it is the wrong part and doesn't allow for the amp's diagnostic function.
 
Last edited:

1LoudLS

Dedicated LVC Member
Joined
Mar 31, 2008
Messages
9,895
Reaction score
356
Location
Ann Arbor
Ive always used resistors in my installs even though our shop has access to 5 volt transistors.
 

ChicoJW

New LVC Member
Joined
Dec 21, 2017
Messages
7
Reaction score
0
Location
Atlanta
Hi! wanted to ask another question. I have not done install...yet because was upgrading the Radio in our old Expedition first -- which I have completed and was about to engage on the Lincoln LS project when suddenly I have an issue with my factory sound system in my Lincoln LS. Out of the blue, I started hearing what sounds like an interference "ignition" noise but only in the driver side door speaker. I also noticed the TXH NAV radio screen flickering a lot. It happens even when the car engine is not running and key is only on ACC.
I researched this and could not find much info online. I believe that there may be some capacitors in the back ? where ? but would these also affect the radio screen if bad. Then do they really go bad like this out of the blue?
Anyways -- any information you can share will be greatly appreciated, specially if someone experience the same thing and has the answer. Wanted to get this solved before I even consider replacing the radio.
Thank you...Chico
 

joegr

Dedicated LVC Member
Joined
Dec 10, 2005
Messages
21,160
Reaction score
2,107
Location
Gulfport
Screen flickering and some clicking noise can be caused by a bad DCCV.

AFAIK, all LSes with THX have a noise tone that happens the first time you go past 2K (or is it 2.5K) RPM while driving. It is supposed to be related to a self test that the AdvanceTrac or ABS runs at that time.

There could be other reasons for your issues too. The LCD backlight is a CCFL, and it will do badly when it is fairly cold. Do the flickers go away after the cabin warms up?

I don't know about any capacitors external to the headunit or the DVD unit that could be involved. Note that video on the screen is all driven by the DVD unit in the back.
 

NickyCapo

Active LVC Member
Joined
Mar 20, 2017
Messages
75
Reaction score
0
Location
Kernersville
I'm finally getting around to the audio system in my 06. I'm trying to search around to see what factory sound system I have in my car. I have the 2 small speakers in center console, would that make my 06 a THX system? The previous owner has some aftermarket stuff in this car. It looks like he pulled a lot of it out before he sold it but, I'm seeing the front door speakers are aftermarket (doing the window regulator, so I noticed Kicker speakers). I am only hearing sound from the Front door speakers. I do not hear sound out of any other speaker. What would be the correct harness to wire in an aftermarket radio to get all the speakers working? If there is one.. He had left in the aftermarket Pioneer double DIN, obviously the speaker inputs on that aren't working. Not sure if he had a amp bypass, or maybe used aftermarket amps to power the speakers.

TIA
 

joegr

Dedicated LVC Member
Joined
Dec 10, 2005
Messages
21,160
Reaction score
2,107
Location
Gulfport
... I have the 2 small speakers in center console, would that make my 06 a THX system? ...

That specifically means that you did not have the THX navigation from the factory. The only factory amps that your car would have had were one for the two small center console speakers, and one for the subs on the rear deck. The door speakers would have all gone directly to the headunit. If the last guy didn't cut the factory connectors, then you can get a wiring adapter kit, but if he didn't cut the connectors, then that kit is already there being used with the aftermarket that he put in. If he did cut the connectors, then there is no use for an adapter harness.
 

NickyCapo

Active LVC Member
Joined
Mar 20, 2017
Messages
75
Reaction score
0
Location
Kernersville
That specifically means that you did not have the THX navigation from the factory. The only factory amps that your car would have had were one for the two small center console speakers, and one for the subs on the rear deck. The door speakers would have all gone directly to the headunit. If the last guy didn't cut the factory connectors, then you can get a wiring adapter kit, but if he didn't cut the connectors, then that kit is already there being used with the aftermarket that he put in. If he did cut the connectors, then there is no use for an adapter harness.

When you say a wiring adapter kit, do you mean the ones that have more than one plug/harness? It has the larger one, with power, acc, ground, speakers etc. And then another plug would need to be wired in to make use of the factory amps, right? Something like whats on this page (i have the 3rd one down):
2006 Lincoln LS OE Wiring Harnesses & Stereo Adapters — CARiD.com

I'll have to check the connections, bc there is no sound coming from the rear door speakers. Are the speakers on the rear deck considered 'subs'?
 

joegr

Dedicated LVC Member
Joined
Dec 10, 2005
Messages
21,160
Reaction score
2,107
Location
Gulfport
Yes, the speakers on the deck are subs only. The adapter for the small connector should have two RCAs on it. One is for the center console speakers. Don't bother with that one. Without the right DSP for the center channel, it's better not to use them at all. The other is for the rear subs. Note that these are mono, not stereo. Your headunit will need to have a mono sub output (many do).
There is also the turn on signal wire for the sub amp and the center channel amp. Leave the center channel amp unconnected. Put a 2000 ohm resistor in series from the remote out of the headunit to the remote in for the sub amp. This will keep it from popping when it's turned on.
 

NickyCapo

Active LVC Member
Joined
Mar 20, 2017
Messages
75
Reaction score
0
Location
Kernersville
Yes, the speakers on the deck are subs only. The adapter for the small connector should have two RCAs on it. One is for the center console speakers. Don't bother with that one. Without the right DSP for the center channel, it's better not to use them at all. The other is for the rear subs. Note that these are mono, not stereo. Your headunit will need to have a mono sub output (many do).
There is also the turn on signal wire for the sub amp and the center channel amp. Leave the center channel amp unconnected. Put a 2000 ohm resistor in series from the remote out of the headunit to the remote in for the sub amp. This will keep it from popping when it's turned on.

Awesome, thanks so much for that info. Exactly what I was looking for!
Note, I do have an amp, powering my aftermarket subs. The remote turn on coming from the radio is connected to my aftermarket amp for turn on. The resistor won't affect that current amp, right?
 

joegr

Dedicated LVC Member
Joined
Dec 10, 2005
Messages
21,160
Reaction score
2,107
Location
Gulfport
Right, aftermarket amp should work with or without the resistor.
 

Dr. Catley

New LVC Member
Joined
Apr 5, 2019
Messages
1
Reaction score
0
Location
Santa Barbara
Hi Joe, I GREATLY APPRECIATE your post on the Aviator THX wiring, and you kindly offered to forward the diagrams at a good resolution if we PM you.

If you would be so kind, I'm at Nick@Catley.net.

Thank you in advance!





I've been having some problems with the tuner in my THX nav headunit. After being unable to repair it, I decided to go after market (JVC KW-NT700).
View attachment 828464687

Fortunately, I was able to retain the factory amps and speakers. I used the following diagrams to figure it out.
View attachment 828464688 View attachment 828464689 View attachment 828464690 View attachment 828464691

Unfortunately, there are no wiring harness adapter kits out there for this. I cut the factory headunit connectors and spliced and solder to the JVC's harness.

View attachment 828464692
This is the "main" connector to the THX nav. You can get a mating connector to this from some adapter kits, but there are only six wires to connect here. Since I could get mates for the other two connectors, I just cut this one off too. Here you get the power connection, the switched connection (in this case, it is the RAP, retained accessory power), the ground, the dash light dimmer feed, and the two wires for the steering wheel controls.

View attachment 828464693
This 18 pin connector is the audio from the THX nav. Even though the pinout says "speaker" these are actually line level inputs. They are differential inputs, but just like the sub input, they work just fine in single ended mode. I connected each of the two amplifier enables to the JVC's amplifier enable output, with a 2.2 K ohm resistor in series with each. No pops.

Now, we move back to the trunk for a moment. This is the connector to the DVD nav computer in the trunk. Note that it is all the same type connector as the "main" connector to the radios. Here, I did use a mating connector from a harness adapter kit I happened to have.
View attachment 828464694
The first thing I did was to connect the two microphone lines to the "audio" lines. This way I was able to get the connections for the microphone in the factory mirror up to the JVC unit (via the re-used "audio" lines). While this did work, unfortunately the factory mic was too quiet and I could hardly be heard using it. I had to switch to the mic included with the JVC. I mounted it on the mirror.
Next, I connected the VSS signal (pin 14) to pin 8, because the "Video Red" signal runs all the way back up front to where the JVC is.
I also connected a reverse gear signal and the video from a reverse camera as indicated. Again, this is all just to get those signals up front. You can run new wiring from the trunk to the front instead if you want, but this saved all that work for me.

Now back to the front again. This is the video connector to the THX nav.
View attachment 828464695
This connector had all the video and control signals between the THX nav headunit and the THX nav DVD/computer unit. Since most of these were only connected between the two units and most of the wires are shielded, I used this wiring to get the rest of the signals needed to the JVC.

Oddly, the JVC only accepted a positive trigger reverse gear signal. I could have tapped this signal at the REM where it sends a positive trigger to the auto-dim mirror, but I didn't. I added a small relay to turn power to the camera on only when in reverse (because the camera got kind of warm if left on all the time). I just pulled the positive trigger signal from this relay, since it was there.


I haven't played with it too much, but so far I like it. It sounds really good to me, and it has many settings for sound, including a lot of DSP stuff.

View attachment 828464687

View attachment 828464688

View attachment 828464689

View attachment 828464690

View attachment 828464691

View attachment 828464692

View attachment 828464693

View attachment 828464694

View attachment 828464695
 

GodbyRdHero

New LVC Member
Joined
May 20, 2020
Messages
2
Reaction score
0
Location
Georgia
Hello joegr,
I have looked everywhere on the internet to do something you did 6 years ago. Connect aftermarket radio to a Lincoln thx system. Your post is great and I want to use the info but is there any way you can upload or email the wiring diagram pics with your notations so that I can read them. This is a headache and I'm trying to keep the factory sub and amp and wire steering wheel controls and DVD retention on a 06 navigator. Please lend your assistance so I can finish this project. Thank you
I've been having some problems with the tuner in my THX nav headunit. After being unable to repair it, I decided to go after market (JVC KW-NT700).
View attachment 828464687

Fortunately, I was able to retain the factory amps and speakers. I used the following diagrams to figure it out.
View attachment 828464688 View attachment 828464689 View attachment 828464690 View attachment 828464691

Unfortunately, there are no wiring harness adapter kits out there for this. I cut the factory headunit connectors and spliced and solder to the JVC's harness.

View attachment 828464692
This is the "main" connector to the THX nav. You can get a mating connector to this from some adapter kits, but there are only six wires to connect here. Since I could get mates for the other two connectors, I just cut this one off too. Here you get the power connection, the switched connection (in this case, it is the RAP, retained accessory power), the ground, the dash light dimmer feed, and the two wires for the steering wheel controls.

View attachment 828464693
This 18 pin connector is the audio from the THX nav. Even though the pinout says "speaker" these are actually line level inputs. They are differential inputs, but just like the sub input, they work just fine in single ended mode. I connected each of the two amplifier enables to the JVC's amplifier enable output, with a 2.2 K ohm resistor in series with each. No pops.

Now, we move back to the trunk for a moment. This is the connector to the DVD nav computer in the trunk. Note that it is all the same type connector as the "main" connector to the radios. Here, I did use a mating connector from a harness adapter kit I happened to have.
View attachment 828464694
The first thing I did was to connect the two microphone lines to the "audio" lines. This way I was able to get the connections for the microphone in the factory mirror up to the JVC unit (via the re-used "audio" lines). While this did work, unfortunately the factory mic was too quiet and I could hardly be heard using it. I had to switch to the mic included with the JVC. I mounted it on the mirror.
Next, I connected the VSS signal (pin 14) to pin 8, because the "Video Red" signal runs all the way back up front to where the JVC is.
I also connected a reverse gear signal and the video from a reverse camera as indicated. Again, this is all just to get those signals up front. You can run new wiring from the trunk to the front instead if you want, but this saved all that work for me.

Now back to the front again. This is the video connector to the THX nav.
View attachment 828464695
This connector had all the video and control signals between the THX nav headunit and the THX nav DVD/computer unit. Since most of these were only connected between the two units and most of the wires are shielded, I used this wiring to get the rest of the signals needed to the JVC.

Oddly, the JVC only accepted a positive trigger reverse gear signal. I could have tapped this signal at the REM where it sends a positive trigger to the auto-dim mirror, but I didn't. I added a small relay to turn power to the camera on only when in reverse (because the camera got kind of warm if left on all the time). I just pulled the positive trigger signal from this relay, since it was there.


I haven't played with it too much, but so far I like it. It sounds really good to me, and it has many settings for sound, including a lot of DSP stuff.

View attachment 828464687

View attachment 828464688

View attachment 828464689

View attachment 828464690

View attachment 828464691

View attachment 828464692

View attachment 828464693

View attachment 828464694

View attachment 828464695
I've been having some problems with the tuner in my THX nav headunit. After being unable to repair it, I decided to go after market (JVC KW-NT700).
View attachment 828464687

Fortunately, I was able to retain the factory amps and speakers. I used the following diagrams to figure it out.
View attachment 828464688 View attachment 828464689 View attachment 828464690 View attachment 828464691

Unfortunately, there are no wiring harness adapter kits out there for this. I cut the factory headunit connectors and spliced and solder to the JVC's harness.

View attachment 828464692
This is the "main" connector to the THX nav. You can get a mating connector to this from some adapter kits, but there are only six wires to connect here. Since I could get mates for the other two connectors, I just cut this one off too. Here you get the power connection, the switched connection (in this case, it is the RAP, retained accessory power), the ground, the dash light dimmer feed, and the two wires for the steering wheel controls.

View attachment 828464693
This 18 pin connector is the audio from the THX nav. Even though the pinout says "speaker" these are actually line level inputs. They are differential inputs, but just like the sub input, they work just fine in single ended mode. I connected each of the two amplifier enables to the JVC's amplifier enable output, with a 2.2 K ohm resistor in series with each. No pops.

Now, we move back to the trunk for a moment. This is the connector to the DVD nav computer in the trunk. Note that it is all the same type connector as the "main" connector to the radios. Here, I did use a mating connector from a harness adapter kit I happened to have.
View attachment 828464694
The first thing I did was to connect the two microphone lines to the "audio" lines. This way I was able to get the connections for the microphone in the factory mirror up to the JVC unit (via the re-used "audio" lines). While this did work, unfortunately the factory mic was too quiet and I could hardly be heard using it. I had to switch to the mic included with the JVC. I mounted it on the mirror.
Next, I connected the VSS signal (pin 14) to pin 8, because the "Video Red" signal runs all the way back up front to where the JVC is.
I also connected a reverse gear signal and the video from a reverse camera as indicated. Again, this is all just to get those signals up front. You can run new wiring from the trunk to the front instead if you want, but this saved all that work for me.

Now back to the front again. This is the video connector to the THX nav.
View attachment 828464695
This connector had all the video and control signals between the THX nav headunit and the THX nav DVD/computer unit. Since most of these were only connected between the two units and most of the wires are shielded, I used this wiring to get the rest of the signals needed to the JVC.

Oddly, the JVC only accepted a positive trigger reverse gear signal. I could have tapped this signal at the REM where it sends a positive trigger to the auto-dim mirror, but I didn't. I added a small relay to turn power to the camera on only when in reverse (because the camera got kind of warm if left on all the time). I just pulled the positive trigger signal from this relay, since it was there.


I haven't played with it too much, but so far I like it. It sounds really good to me, and it has many settings for sound, including a lot of DSP stuff.

View attachment 828464687

View attachment 828464688

View attachment 828464689

View attachment 828464690

View attachment 828464691

View attachment 828464692

View attachment 828464693

View attachment 828464694

View attachment 828464695
 

Members online

No members online now.
Top