CTS-V aux in

Sometimes repairing the stock system is ill-advised but you can do it
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kevm14
Posts: 15200
Joined: Wed Oct 23, 2013 10:28 pm

CTS-V aux in

Post by kevm14 »

There are a few methods for this. The one I am going to do is the cheapest. It basically involves patching in left and right audio signals in place of the XM input, but leaving the XM digital link connected so you can still tune the head unit to XM. At that point, you have simple analog audio input.

There are two ways to do that.

First way (http://www.cadillacfaq.com/faq/answers/ ... index.html) - ignore the part about the PAC input module, as you can also just patch manually:
1) Remove rear shelf to get access to XM receiver
2) Perform patch at the XM receiver
3) Route analog aux in wire from rear shelf up to the front console

Second way:
1) Remove navigation head unit from dash
2) Perform patch at the harness going into the head unit
3) Route analog aux in wire from behind the dash to the front console

I am going with the second option. It actually involves taking apart less stuff, and also is much closer to where the aux in wire needs to go in the first place. Less wire length means less chance for noise, too.

Biggest reason I haven't done this to date: I am afraid of pulling the climate control (lower) and vents (upper) from their clips in the dash to access the bolts for the head unit. That's it. So I finally bought this ($17, https://www.amazon.com/gp/product/B009Q ... UTF8&psc=1)
WP_20160903_11_56_03_Pro.jpg
Should make it pretty easy as long as I pry where the tabs are, without scratching the dash up.

I also was somewhat picky about what cable to use and ended up with this (paid $11, now $12, https://www.amazon.com/gp/product/B00LB ... UTF8&psc=1)
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The 1/8" end is specifically designed to fit in tight places, like a phone with a bulky case. I don't have a case but it seems like a nice cable.

I will probably work on this tomorrow in the garage when the bad weather moves in. All I really want is Pandora while driving. Tired of shuffling CDs and I don't even have most of the music I want on CD anyway.
kevm14
Posts: 15200
Joined: Wed Oct 23, 2013 10:28 pm

Re: CTS-V aux in

Post by kevm14 »

I found some directions for the method I am using.

http://www.cadillacfaq.com/faq/answers/ ... index.html

Confirming wire colors in my FSM.
kevm14
Posts: 15200
Joined: Wed Oct 23, 2013 10:28 pm

Re: CTS-V aux in

Post by kevm14 »

Confirmed.
CTS XM connector.PNG
Time to begin...
kevm14
Posts: 15200
Joined: Wed Oct 23, 2013 10:28 pm

Re: CTS-V aux in

Post by kevm14 »

Here's how it went.

After worrying for 6 years about pulling the clips out that hold the climate control panel and the upper vents, my new plastic trim tool set worked perfectly. Just some careful prying and they popped out. Still a little tricky but way better with plastic tools that won't scratch. Not afraid of this now.
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Upper nav head bolts
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Lower nav head bolts
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Pull these four and it slides right out. Then you have to sit in limbo holding the thing with one hand and disconnecting the two FM antenna cables and 3 electrical connectors with the other hand. You can't put it down on anything as there isn't enough slack in the wires until you disconnect all of them.

Before going any further, I decided to investigate my new audio cable. I cut each RCA end off knowing the conductors inside would be dedicated to each channel. What I found was a little odd.
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The marketing mentions something about this.
E5qJMGyQK2L._UX970_TTW_.jpg
It was a good thing I decided to check continuity with my DVM. I would have thought the red and black were + and - audio, with the outer strand as a shield. Nope. The black and red both went to the tip of the RCA end (audio +) while the shielding worked as the negative. Would have never guessed. I got myself out of the woods twice on this job preemptively (first with the plastic trim tools, and now checking this before installing it). But wait...
kevm14
Posts: 15200
Joined: Wed Oct 23, 2013 10:28 pm

Re: CTS-V aux in

Post by kevm14 »

Since I had confirmed the colors at the nav head harness, I just peeled back some tape and gave them the old snip. Cutting the harness really is kind of a hack but the only thing I would have considered as an alterative is buying the correct female and male connector and making my own pass-through/patch. Just didn't feel like it, so I did this. I could always reconnect the wires but I have no use for XM, and I bet a future owner would rather have aux-in, too. But I digress...
WP_20160905_11_17_03_Pro.jpg
Here are both channels all prepped. I twisted the black and red together on each channel forming a new pair, and then twisted the shields, forming the common. That left me with 3 things to solder to the 3 wires shown above.
WP_20160905_11_17_40_Pro.jpg
I was pretty confident, careful and methodical so I just ran the wire down the dash and along the center console where it exits next to the passenger seat (perfect place).
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I also taped up all the solder connections.
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I stuck the nav head temporarily into the dash and tried my new aux in.

At first it sounded quiet. Then I realized it was much worse than that. The left channel seemed alright but the right channel sounded all garbled. No bass, no vocals. Just bad. I was careful! How could this happen? Here's how:
http://www.cadillacforums.com/forums/ca ... -only.html

Wait, WHAT? The green wire is the common? Not the tan/white like the how-to link AND my FSM told me???

So I had no choice. Pull all the tape, and desolder. First thing I did was connect the common to the green/white. As to the L and R, I had no clue. I was forced to guess. I guessed brown/white was the right channel and I guessed right.

New solder blobs, shittier than the first time I did it.
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The result is now correct. The bass is right and the left and right channels work properly. It is a bit quieter than a CD playing the same source and may have a tad less bass but that could just be the volume difference tricking my ears (or different loudness curves on the volume setting).

6 years later, and I have my DIY aux-in. Now I can listen to Pandora and podcasts and not rely on CDs (good sound, inconvenient) or FM (no comment). Actually I haven't wanted aux-in for the whole 6 years. The first year I had my old HTC Touch Pro (WM) and I don't think I really did music with that. But with my HTC Titan, I think I began to listen to some music and podcasts. Now with my Nokia 1520 I listen to Pandora and podcasts. I got that phone in April 2015 so there's that.
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