Replacing Radio, Extra Wire on Stock Radio Harness? (1 Viewer)

[awesomeissquid]

My 2000 LC currently has the factory in-dash 6 disk CD and Cassette radio (i.e. non-nav). I picked up a Sony XAV-AX5000 and I am trying to wire it up for use. I have both the Metra 70-8113 and the 70-8116. My plan is to try to keep the factory amp with the 8113, but if that doesn't work I can just use the 8116 to bypass it (and lose the sub). I have been referencing the Stereo FAQ and various other threads, but I can not find an answer to my specific questions. My searching over the past few days has not shed any light so I am hoping to get some help.

1. What is the function of the Green/White wire in pin #12 and how does it get used?
   • From the FAQ diagram pin #12 is the Power Supply, ILL(-) and pin #2 is the Power Supply, ILL.
   • The tlcfaq website the stereo wiring diagram shows pin #12 as being empty and pin #2 as Illumination (+).
   • The rest of the wire colors and functions match between the two so I assume the FAQ diagram is correct and that this means both need to be used for the illumination (brightness) control to work. Problem is the Metra 70-8113 harness has no wire connection in that location. I feel like I remember reading something about this needing to get tied into something else, but of course I cant find that now.
2. Is it correct that the Orange wire in pin #7 Mute (Amplifier) and the Green wire in pin #17 Beep do not need to get used?
   • Referencing some wiring schedules everything points to these not being needed, but my brain keeps thinking they must have some function. So anyone know?
3. I was planning to try connecting the three grounds together (2x from factory harness to 1x from new radio harness) Black wire in pin #16 Signal Ground and the Brown wire in pin #20 Ground to the new radio harness ground. Does this sound like a bad idea?
   • Some of the diagrams I found said the new radio ground should be connected directly to the car
   • I thought the above wiring matched what I had read suggested in a few spots on here to resolve the ground issues. Note, I have not yet plugged anything in so I dont even know if I have the pops/hums/buzzing others mention.

 

[gregnash]

#1 is registered as ILL on the MUD list which is the abbreviation for ILLUMINATION. This is your trigger wire for when interior (dash) lights come on with the headlights or with the auto sensor triggering them. So this will allow for your new headunit to sense when the headlights turn on and illuminate its buttons.

#2 I believe this is correct. They are unused when connecting to a new system as the OE system utilized the functions on the amp and not the headunit itself like most modern headunits.

#3 I am interested in this as I still have the ground cycle hum in my speakers after replacing the amp and headunit. I do not remember if I combined the wires to create a singular ground for the system but it would be worth while. Should not cause any issues as it should just been seen as another ground by anything attached.

 

[awesomeissquid]

Thanks for confirming.

I am assuming the system just needs to receive the positive leg of the illumination signal to understand when to switch with the headlights. I am guessing the negative leg is covered by the general ground and that wire (pin #12) is not needed.

I will play around with the grounds and see if that changes anything between them being connected/not.

 

[gregnash]

Correct the negative of the ILL will be just your plain negative because basically think of it as a switched power.

 

[ramangain]

Correct the negative of the ILL will be just your plain negative because basically think of it as a switched power.

Not quite. The correct ILL signal is a variable voltage source, with the voltage level determining how "bright" the illumination is when in the equivalent of "night" mode. I'm unsure if higher voltage means brighter or vice versa.

Somewhere in the past 8 months I put a post in the "What have you done to your rig" sticky on the top which identifies exactly which wire to tap for your HU illumination wire.

 

[awesomeissquid]

Not quite. The correct ILL signal is a variable voltage source, with the voltage level determining how "bright" the illumination is when in the equivalent of "night" mode. I'm unsure if higher voltage means brighter or vice versa.

Somewhere in the past 8 months I put a post in the "What have you done to your rig" sticky on the top which identifies exactly which wire to tap for your HU illumination wire.

Wouldn't the positive side (source) be the one varying the voltage and the negative side would just be to complete the circuit? Trying to remember my electronics classes.

Ill see if I can find your post.

 

[ramangain]

Wouldn't the positive side (source) be the one varying the voltage and the negative side would just be to complete the circuit? Trying to remember my electronics classes.

Ill see if I can find your post.

I think the circuit is completed internally in the HU, and the only input needed for the HU is the actual potential (voltage)

EDIT: This is how my Pioneer NEX headunit is wired. Other manufacturers may employ different circuitry.

 

[awesomeissquid]

Attention all aftermarket radio folks who use a Metra product!

Don't forget to tap the green white OEM wire for your illumination/dimming function. Figured it out and it is all good now.

If I remember correctly, the last Metra adapter that I installed in my son's 2000 LC, did not have an "illumination" wire in it, based on this possibly faulty memory, I'm reading this as "tapping" the factory "illumination" wire and running it directly to the aftermarket head unit's "illumination" lead (not tapped into anything on the Metra adapter).

Okay I believe this is the thread you are talking about.

I also re-read the new HU manual and realized it makes more sense after getting some sleep. Keynote 5 says:

"To a car's illumination signal. Be sure to first connect the black ground (earth) lead to a common ground (earth) point."​

So the common ground covering the negative portion of the wiring is correct and that the positive illumination wire Green, pin #2 is all that needs to be connected.

​

 

[ramangain]

BOOM!

 

[awesomeissquid]

Many thanks! Now to go test it.

 

[ramangain]

Go Squiddy !!!

 

[awesomeissquid]

And....the previous owner screwed me. They had a headrest TV setup installed for the 2nd row a long time ago (~2003). I pulled it out last weekend to get prepped for the new install and found the pin #11 wire cut and run from the center cigarette outlet. I removed that and reconnected the wire thinking that would bring it all back to stock. It seems that line is getting power at all times instead of being ACC power. Caused the surprise of finding the radio can be turned on even when the key is not in/turned on. Regardless the system was getting a slight hum so I am going to go ahead with the amp bypass over the weekend and try to fix it all in one shot.

 

[ramangain]

I thought all ciggie outlet powers are ACC switched? They are on my 01. You may want to check that and start uncovering what other wiring easter eggs are in your rig.

 

[awesomeissquid]

Yea, going to pull the dash and amp apart again to get a clear look at it. I already had the cig outlets buttoned up so I didn't test them this time. The battery and ACC power for the HU is supplied through the amp right? And ACC switched outlets should be dead when the key is not turned to ACC/On?

 

[ramangain]

Yea, going to pull the dash and amp apart again to get a clear look at it. I already had the cig outlets buttoned up so I didn't test them this time. The battery and ACC power for the HU is supplied through the amp right? And ACC switched outlets should be dead when the key is not turned to ACC/On?

Correct on the ACC part. Not sure on the amp part. I still run a Metra harness for ANT, +12V, ACC, and GND for my HU and my ML amp is collecting dust. You can try unplugging your amp and see if your HU still fires up.