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The complete guide to 1st gen CTS Navigation unit installation.

36K views 20 replies 17 participants last post by  Jonny the kids 
#1 · (Edited)
I have put together a definitive list of all the information we have on installing a double-din nav unit in the 2003-2007 Cadillac CTS while retaining the factory DIC. Included in this list are my own contributions along with the works of several other brave men who sacrificed time, expensive electronic components, and blood (from sharp metal edges) to bring you a complete integration procedure.

Physical fabrication for in-dash mounting:

Darkwingfrog Write-up: http://www.cadillacfaq.com/faq/answers/aftermarketradiodic/index.html

Cadillac CTS Sound System wiring schematics:
DIC and Base Amp: http://www.cadillacfaq.com/faq/answers/pdf/wiring.pdf
Bose Amp: http://www.cadillacfaq.com/faq/answers/pdf/bose.pdf
DIC Connector Pinout: http://www.cadillacfaq.com/faq/answers/pdf/wiring.pdf

Wiring Procedure (quick method):

I have decided to list MJS's writeup first, and separate from my own because it occurred to me that there may be users out there who would like to make their install as simple as possible, foregoing all the extra work necessary to make every little detail work. If you are one of these people, the following method is exactly what you want. It's the quickest, easiest way to get a nav unit installed and working in the CTS.

Installing your own aftermarket head unit is VERY easy and it’s not worth paying anyone else more than $100 to do the wiring IMO. If anyone is interested here is how you install and wire a Pioneer F-Series:

1 – Splice the new head to the factory live or wire a new live if you prefer.

2 – Ground the New head.

3 – ACC (ignition) wire on the new head to brown(on mine) wire on the air-con controls.

4 – Audio – Strip the factory audio harness back a little. Cut the factory audio wires about 3 inches from the plug, this leaves plenty of wire to rewire the factory head later if required. Take a good quality shielded RCA cable (monster or equivalent) cut about 18” off each end and strip back the wire until you have +/- wires. Take the RCA wires and carefully splice them to the harness end of the factory audio wire ( green, green, dark green and tan). It is important to get a really clean and shielded join because the RCA/audio cables pick up the old factory radio if the connections aren’t really good. Now plug the RCA cable to your new head.

Now re-install everything but don’t plug the old audio plug into the factory head. Your audio now has two gains, the factory controls and the new heads volume control. I leave my Pioneer on maximum and control the volume with the steering wheel dial.

Still works:
DIC
OnStar (all controls)
Chimes
Both factory volume controls (dash and steering wheel)
Steering wheel buttons.
Factory AMP, speakers and SUB.

You Lose:
XM (an aftermarket add-on is only $75)
New head goes off with ignition NOT by opening the door. Not a problem for me because we rarely sit in a car without the engine on in Florida. You can probably get the RAP working but it is not an issue for me so I am not going to try.

I would like to add that although the factory steering wheel controls do work, it is important to note that only the volume knob and mute button actually control the new nav unit. The "1, 2, 3, 4" buttons will now only control the HVAC and DIC functions.



Wiring Procedure (complete method):
This is my own write-up, however to get to this point I had lots of help. MJS, Kingoftypos, and Gaetano all contributed in some way to the information contained in this procedure.

For this method, you will need the following items:
- PAC steering wheel control adapter (ex: SWI-PS for Pioneer and Sony units)
- PAC OS-2CTS integration adapter (you can omit this if you want to use the ACC key position to signal the unit instead of having Retained Accessory Power)
- 2006-07 CTS-V steering wheel control set (harness not needed)
- 18AWG stranded wire (red, black, yellow)
- 22AWG stranded wire (orange, purple)
- Precision soldering iron

You have two options for giving your unit a turn-on signal (the wire usually marked ACC on aftermarket unit harnesses): The PAC OS-2CTS integration adapter, or the ACC (brown) wire in the CTS ignition harness.

PAC Integration Adapter

This device interfaces with the GM CANbus to facilitate Retained Accesory Power (unit will remain on with all car electronics for up to ten minutes after the ignition is turned off, or driver/passenger door is opened).

MAKE SURE YOU HAVE THE OS-2CTS WIRING DIAGRAM HANDY, AND STUDY IT WELL BEFORE YOU EVEN START THIS PROCEDURE!!

http://archive.pac-audio.com/instructions/os-2cts.pdf

ALSO, MAKE SURE YOU HAVE THE CTS CONNECTOR PINOUT DIAGRAMS HANDY, AND STUDY THEM WELL BEFORE YOU EVEN START THIS PROCEDURE!!

http://www.cadillacfaq.com/faq/answe...connectors.pdf

STEP 1: take the RAD-18 harness from the OS-2CTS and the harness(es) from your aftermarket unit and attach wires color-for-color. The RAD-18 is industry standard color-coded, so this part couldn't be simpler. Make sure you wire all four speakers, antenna, amp turn on, illumination, +12v constant, +12v ACC, and ground.

STEP 2: take the OS-CTS harness (has two plastic connectors on the vehicle side, one black, one red), and cut off both the red and black connectors. Wire according to the diagram on the following page.



With this adapter wired, you will be able to plug in your aftermarket unit and power it up.

Alternate Option - Omitting PAC OS-2CTS adapter

If you do not care to have functioning RAP or OnStar, you may omit the OS-2CTS adapter altogether.

Wire according to below diagram:



Turn on (ACC) power - In this case you will use the ACC wire off the CTS ignition harness (found under the steering column inside the driver's lower-dash kick panel. The panel is removed with three screws all the way at the bottom and three metal/plastic clips at the top. You can simply tap into the brown wire coming off the ignition harness (TAP, DO NOT CUT!) to supply turn-on power to your unit. The picture below shows (a blurry version of) this wire.



Illumination - There are several places to get the illumination signal from. The orange wire coming off the turn signal stalk harness is one. If anyone knows of a better wire, let me know and I will add it here.

Steering wheel controls

The simplest way to do the install is to leave the factory steering wheel controls connected as they come, to the DIC. However this means that you cannot program the 1,2,3,4 buttons as track/folder/disc advance. Basically you only have volume and mute. You can purchase a PAC translator and use it with the factory controls, but then you can't use the volume knob. You would have to program two of the 1,2,3,4 buttons as volume, and the other two as track advance. Then you have a dead volume knob and mute button. The solution? CTS-V controls. Swap a set of CTS-V steering wheel controls onto the steering wheel. To do this you will have to completely rewire the factory steering wheel harness (wires behind airbag in wheel).

Use the below wiring diagram for rewiring the stock CTS harness for the CTS-V controls.

 
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4
#2 · (Edited)
Tweaks and fixes

Eliminating interference in the low-voltage lines to the amp

Even if you very carefully wire your connections to the factory amp wires from the DIC to attempt to maintain shielding, you will sometimes still encounter static or clicking in the speakers. There is at least one way to completely remedy this situation once and for all. This is what I like to call "old school".

Get yourself a good set of brand-name pre-amp RCA cables in a size long enough to make it to your trunk-mounted amp (16-20ft is generally the accepted average). I also recommend obtaining some pre-wired female RCA tails so you don't have to lop the plugs off your high-end set. If you have stereo crap laying around, you could also find a cheaper RCA cable to cut in half (even if it's a single cable, you would end up with two pre-wired plugs. If you go this route, you will need a two-channel coupler (see Radio Shack for this one) to join the wires to the tails.

Plug the good cables directly into your aftermarket nav unit, and run them to the trunk. You can run through the center console and under the rear footwell center hump, under the back seat and into the trunk. You can also run to either side of the car and use the factory harness channels under your door sill trim. Whatever you prefer. Once you get to the trunk, you will need to cut into the factory harness at the amp to attach your RCA tails. Below is a pic of the factory amp harness.

From left to right, the bright green is R-, the dark green is L-, the brown is L+, and the last bright green is R+.



LED Button lighting not working after install.

I was warned that this could be a problem after my install, so I paid careful attention to where I cut the DIC
board, and noticed that when cutting the lower part of the board off (per the Cadillacfaq.com how-to), you would be cutting off the trace that feeds the right-side button LEDs (specifically the LCD right-side toggle programmable button, the clr/info button, and the swish above the selector knob), and a dropping resistor. I tried to find a way to cut the board so as to avoid this problem, but there was no way I could cut the board to preserve the circuit and still fit my nav unit in the enclosure. So I reluctantly cut, and ended up with the dead lights that others had warned me about. This really bothered me, so I decided to fix the problem. Here is the process.

This pic shows the non-functioning LEDs...notice the right side of the LCD (two LEDs not working), and the right side daughtercard (four LEDs not working).



Upon dissasembly, I traced out the circuit that feeds these LEDs. The red lines in this pic denote the traces that normally exist to feed the affected LEDs. The yellow box denotes the location of the dropping resistor for the lower
LEDs on this circuit. You can clearly see how cutting where we need to cut to fit double-din units affects this circuit.


The grey line in this pic shows the dead part of the circuit, the red represents the live parts. The orange shows my proposed jumper solution. It simply jumps supply power across the gap in the circuit, using two conveniently placed transfer holes already in the board.



I used a jumper of 18AWG stranded wire, of which I cut off about half the strands to fit the holes (22-24AWG would be ideal and require no cutting). I then inserted the wire in the holes and soldered from the other side of the board. Be very careful with the soldering part...it is very easy to accidentally short out this trace because the common plate runs within 0.5mm of it. A precision low-wattage soldering iron and light-guage solder is a must.



Not the greatest pic, but you can see the lights are back on. Mission accomplished.

 
#5 ·
Wow, nice guide.

I have a little question about the Navi Unit.
I confounded the plus and minus wire on my car and connected the battery wrong, so plus to minus and vice versa.
Since that my Navi Unit isn't working anymore, it seems there is no electricity. So I think there is a blown fuse somewhere.

Do you know where all the fuses for the Navi Units are?
Is there a fuse on the Unit itself?
 
#7 ·
Installing your own aftermarket head unit is VERY easy and it’s not worth paying anyone else more than $100 to do the wiring IMO. If anyone is interested here is how you install and wire a Pioneer F-Series:

1 – Splice the new head to the factory live or wire a new live if you prefer.

2 – Ground the New head.

3 – ACC (ignition) wire on the new head to brown(on mine) wire on the air-con controls.

4 – Audio – Strip the factory audio harness back a little. Cut the factory audio wires about 3 inches from the plug, this leaves plenty of wire to rewire the factory head later if required. Take a good quality shielded RCA cable (monster or equivalent) cut about 18” off each end and strip back the wire until you have +/- wires. Take the RCA wires and carefully splice them to the harness end of the factory audio wire ( green, green, dark green and tan). It is important to get a really clean and shielded join because the RCA/audio cables pick up the old factory radio if the connections aren’t really good. Now plug the RCA cable to your new head.

Now re-install everything but don’t plug the old audio plug into the factory head. Your audio now has two gains, the factory controls and the new heads volume control. I leave my Pioneer on maximum and control the volume with the steering wheel dial.

Still works:
DIC
OnStar (all controls)
Chimes
Both factory volume controls (dash and steering wheel)
Steering wheel buttons.
Factory AMP, speakers and SUB.
Is this really all I need to do to get an aftermarket head unit working with DIC?
 
#15 ·
Might not have an active photobucket account anymore or it could be the op has not changed the settings in his photobucket account. Photobucket has done some changes and pictures were not showing. you have to go in your account and disable Easy Linking.
 
#16 ·
Does anyone know where the front channel line splits to the door/tweeter? I know it comes out of the amp as 1 signal. I know the tweeter line runs along the headliner and im pretty sure the door speaker line runs along the floor. I need to tap in with a crossover for my Kappa components. I'm NOT trying to run my own wire. Please help 🙏
 
#17 ·
I would recommend the moderators split this question out into it's own topic, as it doesn't really apply to the original thread.

There are two speaker configurations on the CTS, only the U57 has a split in-line. If you're confident of the split, or can verify RPO U57, then your wiring should be as follows:

Starting at the Amplifier located in the rear compartment, to the rear of the left strut tower, the wiring runs to Splice Pack 300 (SP300) located In the passenger compartment, on the left frame rail, near the left side of the driver seat. Left Front signal is Yellow and Tan wires, Right Front is Purple and Light Green Wires. From SP300, the door speakers run separately to C500 (Left Door) and C600 (Right Door). Both pillar speakers run back to the headliner harness connector C308 (Headliner harness to the body harness, in the passenger compartment, on the left C-pillar) before running back forward to the individual pillar speakers.

The "Split" occurs right in SP300.

If you need to separate the speakers (inserting your own crossover), that's the place you have to do it.
 
#18 ·
Hello all. I've been on here about 10 years and don't talk a lot but I read here some and saw this. I'm getting close to finishing this up in my 03 CTS Luxury Sport and was just wondering if anyone had any kind of RAP fix. I didn't want to double post it if someone else had but I have a solution for mine with no extra modules and thought if it wasn't out there maybe I could help.
 
#20 ·
Morning Johnny. Mine is a 2003. I grabbed mine directly from the RAP mini relay output that runs the RAP for the sunroof. I tapped into the relay output under the rear seat and ran it back up to the head unit. I was running rear camera wiring from the new head unit and already had the left side panels off and rear seat bottom out so I figured that was the easiest way to do it.

You will be looking for a heavier dark blue wire coming out of the RAP mini relay. Once the rear seat bottom is out and the carpet pulled forward you can see it and the other wires for the relay by just looking through the spot where the wiring harness enters the right rear fuse block viewing it from outside the right rear door. There's no need to pull the fuse block out or apart if you don't want to, you can unwrap the harness outside the block and tap into it. The wire heads toward the rear of the car, I actually opened up the harness in a spot under the rear seat where it was real easy to get to and made the tap there.

I took some screen shots from my Alldata program this morning, what you are looking for is all highlighted with a yellow circle. There is also a yellow arrow pointing to exactly where that blue wire you can see will be. Sorry I don't have any real pics, the job has been done for many months.

596315
596316


596317
596318
 
#21 ·
Morning Johnny. Mine is a 2003. I grabbed mine directly from the RAP mini relay output that runs the RAP for the sunroof. I tapped into the relay output under the rear seat and ran it back up to the head unit. I was running rear camera wiring from the new head unit and already had the left side panels off and rear seat bottom out so I figured that was the easiest way to do it.

You will be looking for a heavier dark blue wire coming out of the RAP mini relay. Once the rear seat bottom is out and the carpet pulled forward you can see it and the other wires for the relay by just looking through the spot where the wiring harness enters the right rear fuse block viewing it from outside the right rear door. There's no need to pull the fuse block out or apart if you don't want to, you can unwrap the harness outside the block and tap into it. The wire heads toward the rear of the car, I actually opened up the harness in a spot under the rear seat where it was real easy to get to and made the tap there.

I took some screen shots from my Alldata program this morning, what you are looking for is all highlighted with a yellow circle. There is also a yellow arrow pointing to exactly where that blue wire you can see will be. Sorry I don't have any real pics, the job has been done for many months.

View attachment 596315 View attachment 596316

View attachment 596317 View attachment 596318
Nice, but for some reason in 2005 Cadillac removed that rap relay mini, and is no longer in the fuse boxes 2005-2007
 
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