Metra install - need installer advice / sanity check

[SS Drifter]

Edit - Not getting any responses, here is a short version.

Installing metra and need to tie 3 mute interupts to head unit, Metra module, BT module and 9500ci. Per customer support the 3 interupts require diode isolatation. If a resistor is required to fix the metra mute issue, which side of the diodes should it connect to? I'm guessing the head unit side but, don't know for sure.

If interested, there is more info below from the origial post.

Alpine CDA-117 with KCE-400BT
Amp: Audison SRx 5
Speakers: Hertz HSK 165 front and rear
Sub: JL Audio 8W3v3-4

While building the sub box and mounting the amp I am planning the Metra and head unit installion. The head unit is a single DIN Alpine CDA-117 with the KCE-400BT (Parrot based) blue tooth module. I went single DIN for audio quality plus, I prefer a separate PC/GPS solution for ease of upgradability.

The OEM amplifier and center speaker will remain in the car for chimes and Onstar voice. The head unit pre-outs and aftermarket amp will connect directly, without passing through the metra interface. I'm planning to connect the audio out from an existing Passport 9500ci to the OEM amp. In think the low level out from the 9500ci can connect directly to the available low inputs of the Metra.

There are three devices that can generate an audio interupt to the head unit; 1.) Metra, 2.) 400BT and 3.) 9600ci. Alpine customer support (Crutchfeild) recommend's diode isolatation of the the interupt lines. I was originally planning to go one step further by diode isolating and using a relay that any interupt could pull closed. The relay contacts would then bring the head unit interupt input to ground.

So now for my questions.
1. Does anyone see a problem with connecting the 9500ci low level out to the metra low level in?

2. On the interupts.
a. Is the relay overkill?
b. If I need a resistor to get around metra interupt issue (head unit turns off rather than mutes) would I install it on the head unit side or metra side of the interupt?

If anyone sees potential problems with this layout please let me know. I'm trying to get the guess work out of the way before taking the dash apart.

[CamaroGeek]

OK, I'll play.

I see no problem with using the 9500ci outputs directly into the Metra low level inputs. You will want to drive both front RCAs, and leave the rears open. The kit will only pass the audio when it thinks the radio is on, meaning that the blue/white wire on the 20-way connector must be driven high. The gain pot should be used to adjust the nominal volume level of the 9500ci audio.

You might have to educate me on the interrupt issue. Why does the head unit need to be interrupted, and what does it do when it gets an interrupt signal?

As for the shut-off during OnStar or OE BT, you will want to pull up the mute output wire on the Metra kit with a 10K resistor or so. That way the kit will think that there is a mute-capable radio attached, and will not kill the accessory wire during OnStar ops.

[SS Drifter]

CamaroGeek - thanks for playing. I'm all ears when it come to good advice. I've read some of your other posts and it's apparent that you know your stuff.

Connecting the 9500ci to the two front inputs on the metra is what I had in mind. The 9500ci has a volume control but, adding a pot makes sense. Is the PAC LC1 suitable or do you recommend something else?

To drive the blue/white remote wire high my thought is to just connect it to the red ign/acc wire on the Metra 20 pin connector.

I've been using the term interupt for mute, perhaps my terminology is incorrect. The goal is to allow the 9500ci or Onstar to mute the head unit while the OEM amp/speaker(s) has an active input. This should also give the 400BT the mute connection that it requiures.

If I understand your last paragraph correctly, I could pull up the brown wire on the Metra 20 pin with a 10K resistor that is also to connected to the red ign/acc wire on the Metra 20 pin connector.

I'm open for corrections if didn't catch something quite right. Thanks again.

[CamaroGeek]

You don't need an external volume control - use the system gain pot on the interface. The pot closer to the corner of the board is the gain pot. The other one adjusts chime volume after you have set the gain.

You should be able to tie all of the mute/interrupt wires together. They are usually open-collector active low, meaning that they will pull low when they want attention, but will not pull high. So anybody that tries to pull it low will succeed. You could diode isolate if you want to be safe, there is not downside to that. I wouldn't bother with a relay - that may cause more trouble than it solves.

Your connection of the mute pull up resistor is correct, although it may not even be necessary. I'm not sure what Alpine uses to pull up, but I have not heard anyone complain about it (I have heard complaints about Kenwood and Pio).

[SS Drifter]

That's great info. Thanks again.

It might take a couple days to get the point where I can test. I'll post my results for anyone taking this path in the future.

[jimmie.briseno]

well today i took my camaro in due to a muting issue during Onstar operations. I have until now thought that the radio shutting off during Onstar and BT was normal for the radio (Clarion NX500) but finally took it in to get looked at and the installed called metra and tried the 10K resistor to the brown mute and red acc wire and the radio stayed in mute mode.

he called metra back again and they said try a 300k resistor and that didnt work now he is keeping my car over night and Metra is trying to find a fix for the Clarion head units.

now in the post i read that you also needed diodes in series with the resistor is that correct? any info would help since metra and my installer cant fix my muting issues right now

[Silver Ice Man]

WOW , I thought this metra kit was supposed to be a plug and play unit.
Glad I didn't try this one on my own yet.
I will be watching this closely as I may attempt this in the spring now.

[SS Drifter]

It probably is more or less plug and play in most cases when you want stay generic and run the factory amp and speakers.

Does anyone have a good source for connectors? I need the 16 pin, amp X2 connector in both male and female to build a jumper/breakout to drive the front speakers off my new amp. I know the alternative is cutting the harness but, this destroys some of the cars original value.

I'm trying to give the connector search a fair shake but coming up empty handed. I could probably find the female connector through the GM part number but, I really need the mfg and series number to find a matching male plug.

[SS Drifter]

Originally Posted by jimmie.briseno

now in the post i read that you also needed diodes in series with the resistor is that correct? any info would help since metra and my installer cant fix my muting issues right now

Jimmie - In my case I'm using three devices that can mute the head unit. The diodies are just a little extra precaution. They may not be necessary.