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[HOW-TO] AUX (Line-in) on CTS without sat radio

115K views 76 replies 42 participants last post by  joekirscht 
#1 · (Edited by Moderator)
First of all, please excuse me for my english, it's not my native.
Second, I know, I know, you can add AUX line-in to your radio using some kits. But they all require satellite radio installed, which is not an option for European cars. Anyway, may be someone could find it useful.

So here we go.

A little bit of theory.
As we know, CTS has an amp installed (located on the left of trunk). As I find out, volume controls affects not the radio itself, but controls amp directly. So all what we have to do is to replace sound line with our line-in, and we'll keep all volume controls works.

There are two channels on every mp3 player - left & right, each channel has 2 wires: signal (+) and ground (-). In most cases, both channels has shared ground wire. But, in our car there are two separate grounds (so we'll get less noise).

So everything we need to do is to switch 4 wires (+ -, 2 channels).
The best way to do this is use two relays.

Lets get started

What we need:
1. TR99-12VDC-SB-CD relays – 2 pc. (about $4 each) or similar.
2. Switch - 1 pc, ($1-2).
3. 3.5mm socket ($1-2).
4. Few colored wires.
5. Soldering iron and stuff
6. Piece of cardboard
7. Small plastic box (i've bought one in radio shop, together with relays, for $2).

Step 1. Preparing line-in socket.
Take any 4-wire cable and solder it to your socket. One wire to the left contats, one to the right, two wires to long one (that is common ground).


So now we have a 3.5mm cable


Step 2. Relay box
The best way is to make a circuit board, but I didn't have a tools so I just picked an air freshner made of cardboard.


Now make a holes for relays' contacts


I've put a little schematic on the back of the board so I didn't get confused. Both relays sit in holes.


Take a soldering iron and solder colored wires like this:


After soldering work is done, I put everything in this little box and marked wires.
 

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#2 · (Edited by Moderator)
Step 3. Installing relay box to the radio.

Take off your radio. Here's a link that can help: http://www.cadillacfaq.com/faq/answers/radbezel.html

Look at your radio's connectors. We need this brown one. Look closer - there are two pair of wires - 2 light greens (L channel), dark green and dark orange (R channel). Cut them, and install relay box. AMP wires to the side that goes inside car, HEAD wires to your radio side.


After that, you can use velcro tape to stick relay box to the upper right corner of your radio, so it will fit back to dash.


Now you have to decide where to put line in socket and a switch. I choose a free space near cigar lighter.

Using hot knife cut a hole and put a switch in it.




Now we have to connect control wires to +12 and GND. The best way is to use cigar lighter's wires. One wire to the ground(black) and to relay box, other wire to +12(red) and to the switch. One more wire from the switch to control box.


Now put your radio back to dash and have fun!


Here's a video of how it works.
 

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#5 · (Edited)
Nice write up, I didn't read it all because I already knew the fact the amp did all the audio adjustments. But the reason for my post is the fact that you should already have RCA hook ups. They should be located under the center arm rest, or with in it. This because of it being an European car, they obviously forgone the XM radio. Instead, they installed the RCA inputs. At least I've seen it on here with lots of other European cts'.

KOT

How did that air fresher smell like before you screwed holes in it? Lol
 
#9 ·
Hello,
I just finished installing a Scosche IPFMRDS FM RDS iPod Interface in my '03 CTS factory radio. It worked better than expected and very easy to install. The painful part was waiting a month to get it from Crutchfield. Next, Boss 1800 watt amp install.

Ryukhan44
 
#10 ·
Hi Ryukhan 44
New to the forum. I am leaning to purchase the scosche ipfmrds. I do not have xm on my stock radio (2004) cts. Does the wire harness supplied with the unit just plug into a port from the cd changer like the Crutchfield info says? What (red) hot wire did you tie into and the same ? for the white?

Beachnau
 
#16 ·
Great write up, well done! I have the non xm radio and desperately want a AUX port because I usually listen to Pandora thru my phone. Currently, I am using a FM modulator, the sound isn't horrible but certainly not as good as what you have done here. Since the write up was so well done, I may just tackle it myself!

Thanks again
 
#17 ·
First off, let me just say awesome write up. It was very easy to follow. I just got done adding this set up to my 2003 non navi/ xm CTS and I must say that I'm pretty impressed with the way it came out. The only downside is that I am not getting any sound out of my sub. Any thought or ideas on what caused that and how I can fix it? Any feedback is appreciated. Thanks
 
#18 ·
Just an update for folks who, like me had never attempted a project like this, and had no idea how to read a relay on a circuit diagram before this.

I'm in the U.S. and we have Radio Shacks on practically every corner here. I did this almost with all Radio Shack parts.

Phone Jack:
Radio Shack part number 274-0249 (2 to a pack, I needed 2 because the pins are delicate and I broke the middle one while soldering)
PCB:
Radio Shack part number 276-0148 (perforated in the middle so you can use the whole thing, or just half. I only needed half for this project)
Box:
Radio Shack part number 270-1802 (fits the PCB above perfectly, you'll need to drill holes in the side for wires)
Relays:
Radio shack part number 275-0249

I used a switch from AutoZone because I didn't like any of the ones they had at Radio Shack, though they had a bunch available. The one I have is a simple black rocker switch with a blue LED that illuminates in the "on" position.


The pinouts on the relays I used are different from those on the relays the OP used, so I figured it would be helpful for a lot of folks who are in the U.S. where these parts are easy to find, but who don't have a deep understanding of the principal.

Below is the wiring diagram for the parts I used. Even if you understand very little of how this works, if you can operate a solder iron, you should be able to make this work by copying this diagram using the parts above, and some wire. I hope this helps someone.

Diagram Line Floor plan Parallel Technology
 
#72 ·
Just an update for folks who, like me had never attempted a project like this, and had no idea how to read a relay on a circuit diagram before this.

I'm in the U.S. and we have Radio Shacks on practically every corner here. I did this almost with all Radio Shack parts.

Phone Jack:
Radio Shack part number 274-0249 (2 to a pack, I needed 2 because the pins are delicate and I broke the middle one while soldering)
PCB:
Radio Shack part number 276-0148 (perforated in the middle so you can use the whole thing, or just half. I only needed half for this project)
Box:
Radio Shack part number 270-1802 (fits the PCB above perfectly, you'll need to drill holes in the side for wires)
Relays:
Radio shack part number 275-0249

I used a switch from AutoZone because I didn't like any of the ones they had at Radio Shack, though they had a bunch available. The one I have is a simple black rocker switch with a blue LED that illuminates in the "on" position.


The pinouts on the relays I used are different from those on the relays the OP used, so I figured it would be helpful for a lot of folks who are in the U.S. where these parts are easy to find, but who don't have a deep understanding of the principal.

Below is the wiring diagram for the parts I used. Even if you understand very little of how this works, if you can operate a solder iron, you should be able to make this work by copying this diagram using the parts above, and some wire. I hope this helps someone.

View attachment 89518
So instead of a pair of relays, couldn't a simple pair of DPDT switches work to choose between the head unit's audio and the AUX audio?
 
#19 ·
atorres - My guess is you wired your amp for your subs to get its input from the cars stock subwoofer? Now, im not intirely sure, but i don't know how the left and right wires could possibly also distribute sound to the sub. If im thinking this right, your subs just arent getting any input, maybe there needs to be another wire? Im curious now as im about to do the same thing and I have subs also,, tried a different tactic today that failed :( , but on the bright side - I didn't cut any wires...I just want better quality than them stupid fm transmitters.
 
#28 ·
Tlorenzen, Thanks for the response and i must apologize about the lapse in time between posts. Anyway, what i found, upon further inspection, was that I was actually getting some sound from the sub but it was barely being pushed...very minimal sound coming from the sub while the mid's and high's sounded perfect. I lost interest in figuring it out so I've been using the cd player but my collection is now becoming hard to manage...anyone on here with any other thoughts on how i can get better sound from the sub? Again, I used the diagram provided by Dronix, no other modifications.
 
#20 ·
I was reading this and noticed that some people said they dont know how to turn on their RCA inputs under the center armrest if fitted, mostly to euro spec cars, there is a reason for this, I found that my CTS had the TV/VCS fuse swapped out to a spare location, I swapped it back and the TV started working, if you then press the SEL button/knob it will let you switch between TV and Aux in, my aux in works just great :)

Hope this helps

Stu
 
#21 ·
CTSUK said:
I was reading this and noticed that some people said they dont know how to turn on their RCA inputs under the center armrest if fitted, mostly to euro spec cars, there is a reason for this, I found that my CTS had the TV/VCS fuse swapped out to a spare location, I swapped it back and the TV started working, if you then press the SEL button/knob it will let you switch between TV and Aux in, my aux in works just great :)

Hope this helps

Stu
Hey Stu
Just looked into the fuseboxes under the backseat. How on earth did you find out wich fuse to swap? I have the Aux under center armrest and would very much like it to work.
/jasper
 
#22 ·
Hi Jasper,
It is in the same fuse block as the trunk diode passengers side I believe (or drivers side if it is a right hand drive car).
It is in the same row that the fuse puller is, its label is TV/VCS, if there is no fuse in place then you will need to buy one or if there is a fuse in the spare locations of a 10A (red in colour) rating use that and place it into the TV/VCS fuse slot, from the "Joint connector" it is the first fuse hole that you come to after the "spare" relay location.
 
#24 · (Edited)
#29 ·
It sounds like it may be connected out of phase, ie positive to negative, negative to positive at some point. Most likely with the 2 light green wires....crazy they made the same color!

When I did this mod, I cut the wires inline with the auxiliary input, soldered RCA connectors on each side, and installed a 6 volt line driver because I found the sound was much lower than the fm radio and cd sources.
 
#31 ·
I have a non-XM non-navi US-spec car with Bose. I don't think I have RCAs in the center console, but I wish I did.

Instead of cutting wires on the GM wiring harness, has anyone figured out the connector part# and reverse connector part#? If we had that, we could buy two connectors, wire straight across for every signal but the six we need, and make the splices on the adapter we're making. This way it would be really easy to take the relay and input circuit in and out without cutting the stock wiring harness.

So, anyone have these part# ?
 
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