2007 Denali radio replacement

[chris4851]

I have a replacement radio that I want to install in my 07 Denali. The stock radio has Nav, with Bose and rear seat entertainment. I am at a loss to which harness I need to purchase. At this point I do not care about steering wheel controls and the On Star. I would like to use my stock Bose amp and stock rear seat TV. Does anyone know what harness I might need? The OS-4 looks to be a complete package but I do not need all the bells and whistles, plus its $220.

Power harness?
Audio harness?
Overhead rear TV? Pac Audio: GMRVD?
Antenna?

[jmac572]

you will need the GMRVD for the rear seat entertainments... the OS-4 is the best option for radio replacement in denalis and escalades and includes audio/power/antenna adapter/and retention of ALL stock options... and the steering wheel controls are very very easy to retain, PAC makes 3 different steering wheel interfaces for GM Full size truck/suv's i believe, what brand is the radio?? if its a strange brand that you cant find a compatable harness for you can use the PAC SWI-X, which works for almost all aftermarket radios that include a remote, it learns the IR signal from the remote control for the aftermarket radio and hooks up to the vehicles wiring harness (simple connection that the OS-4 has a output for) and when u hit, say, the volume up button on the steering wheel, it will send out the same IR signal that the volume up button on the remote that came with the radio... look on ebay, youll find all 3 of those combined for less than $250 shipped... get the OS-4, its best to keep all your factory options... you might not know it, but if you dont get the right harness youll loose your turn signal audio, backup sensors, onstar, and a couple other things too, just curious, why would u want to get rid of the stock nav??

[chris4851]

Thank you for the reply jmac572. After further research I will be going with the PAC OS-4. Does the OS-4 include the rear seat entertainment harness? I have also found Scosche GM21SR, do you know if this has the same functionality? Say's it will retain Onstar and chimes.

As much as I do like the stock Nav/radio with the lockpick it cannot compete with a full car PC. I have an indash full car PC with 6.5" VGA LCD/DVD/Nav/phone/MP3/Internet/TV/anything else you can do with a PC. This unit has a 50x4 internal amp also.

[jmac572]

nice, that explains it i guess... there are 4 or 5 companies that make a similar item to the OS-4, but in my opinion the OS-4 is the best and although i have not tried any other products, the OS-4 promises to retain more factory options than others... for example, with the GMOS-LAN-05 made by Metra AXXESS, the onstar volume is adjusted using a small knob/button on the harness itself behing the radio, with the OS-4, onstar volume is adjusted using the steering wheel/radio volume knob when onstar is active (just like from the factory) the other reason i suggest using the PAC part, is because if your going to do all three, IMO, its best to keep them all from the same manufacturer... like i said before, the OS-4 has the outputs for a steering wheel control adapter making that part a snap.

The OS-4 does not come with the GMRVD, thats a separate purchase and when installed is completely separate from the OS-4, your factory NAV head unit has 4 connections that all look the same, two are used with the OS-4 and one of the other ones is used for the GMRVD, which turns that factory harness into RCA cables so you can hook it up to your new head unit's RCA video outputs. All together youll need...

OS-4
GMRVD
SWI-X

good luck, anything else, just ask

[chris4851]

Jmac: I'm at a loss right now. I purchased the OS-4 and have made my connentions but am getting no audio within the car. I know it is not the head unit because I have tested the audio out on my workbench.

My head unit has a built in 50x4 amp. I have tried the "factory amp" and "no factory amp" connections with the OS-4 with no success. Any suggestions?

[sdgd711]

Did you hook up the factory amp turn on? It is usually a blue with white stripe off the aftermarket head unit, although it may be different with a full PC. There should be a blue w/ white stripe (or solid blue on some models) on the OS4 also, this is what turns on the factory amp. Even though you have an amp in the new head unit, the Bose amp still needs turned on. If there is no amp turn on on the aftermarket unit, you can use the red ignition wire off the OS4, although if you do this make sure you are connecting to the output of the relay. The only difference is that the Bose amp will stay on when you power off the new head unit with the power button on the unit.

[chris4851]

Thank you sdgd that worked! However I had to use the red ignition wire. Are you saying that the factory amp will remain on bu this method? Will it shut off when the door is opened or after 10 minutes?

Also, I am getting some serious line noise now. Prior to even having the radio on the line noise is horrible.

[Modded]

You need a ground loop isolator to kill the radio noise.
With a turn on lead like the OS4 has, its supposed to urn on ad off your amp. Some amps even ahve input sensors for that function so they follow whether the radio is on/off.

[chris4851]

Do I need a ground loop isolator for every speaker? Where would the GLI go?

[sdgd711]

The factory amp will shut off just like normal when you turn the truck off and open a door. A ground loop isolator works sometimes and sometimes it makes it much worse. Since you are using the Bose amp a ground loop isolator will not work, they are made for RCAs to aftermarket amps not wire to wire. Before you do anything as far as rewiring try to find an inline power/ground filter and put it on the 12v and ground wires of the new radio.

The 2007+ GM trucks are notorious for noise issues. If the power filter doesn't work I ususally try doing the following. The first thing is to common ground all of your componets. Try moving the ground from your new head unit (and whatever other componets you have) to the ground wire in the factory harness (basically bypassing the ground in the OS4 harness). If that doesn't take care of it try the driver kick panel. Make sure you scrape the paint all the way down to bare metal before you screw the grounds in. If you're still getting noise the next step would be to ground the new head unit and the factory amp in the same spot. The Bose amp is under the center console and I'm not sure where GM grounded it, so you would have to get to the amp and trace it back to wherever it goes. After that you can check the resistance to ground from the main ground at the battery to where you are trying to ground your stuff to see if it's a clean ground. There are more things that can be done, but one of these will usually take care of it.

I know this sounds like a lot of work, but I have spent hours trying to get rid of noise in these trucks when trying to integrate into the factory audio and it can be incredibly frustrating, but obviously the alternator whine is something that most people can't live with.

[Modded]

I have always wondered why grounding is supposed to be on a complete paint free surface??

[chris4851]

sdgd: Something like this?
http://www.pie.net/pie_store/shopdisplayproducts.asp?id=20&cat=Power+Filters

[sdgd711]

No, you will need one that has a 12v and a ground coming out of both sides. The filters that I have always used were the ones that came on the harness of the Pioneer navigation units. I can't guarantee that it will get rid of the noise entirely, but it might be worth a shot.

Here is a link to one of the harnesses. The filter is obviously the black box with the yellow and black wires coming out of it.

http://cgi.ebay.com/PIONEER-WIRE-HARNESS-DEH-P8600MP-P6900UB-P960MP-pi16-5_W0QQitemZ360105541009QQcmdZViewItemQQptZLH_Defau ltDomain_0?hash=item53d7f67d91&_trksid=p3286.c0.m14

[chris4851]

I have found and ordered one, comes Monday. Thank for the help guys. I notice when I hook up to the front speakers the audio comes out of all the speakers. For example, Front Left plays on both the front and rear left side of the car. Is this common in these vehicles?

[chris4851]

So I have everything installed and working 95%. I notice an issue with the audio not turning on when starting the vehicle with the door closed. Here is my setup.... I have attached the remote amp wire to the OS4 red ACC wire. As someone pointed out this will work if my after market radio does not have a remote amp wire. The audio only plays when the vehicle has been started with the drivers side door open. If the door remains closed while the car is started no audio will be heard. Any thoughts?

[sdgd711]

Try taking the amp turn on off the OS4 acc wire and temporarily hook it up to the 12v battery source (yellow wire on the OS4) and try starting the truck with the door closed. This will tell you if it has something to do with the acc wire on the OS4. Did you make sure to hook up the acc wires on the output of the external relay on the OS4?

[chris4851]

I will give this a shot (hooking the amp turn on to the yellow 12v source). However I did hook up to the output of the external relay. I was beginning to think that this might need to be hooked up before the relay as the relay might not be allowing the amp to turn on quick enough? Or is this relay used to shut the power to the 12v ACC once the door is opened?

[sdgd711]

The acc wire coming directly out of the OS4 is a very low current wire. They add the outboard relay so you can hook up more than just the radio acc to it. This probably goes without saying, but make sure you don't leave the amp turn on connected to the 12v battery wire permanently.

[chris4851]

I have hooked up to the constant 12V source and yes the audio works with or without the door closed when starting the vehicle. I assume that this works fine as the factory amp is ON all the time.

I have went back and hooked the remote amp wire to the ACC 12v source and still have the same issue with the audio playing if the door is closed when I start the vehicle. I guess for the time being I will need to remember to keep the door open when I start the vehicle. Anyone else experience anything like this?

Do you think this has anything to do with the RAP system in the vehicle? I have used a multimeter and measured the 12v ACC line and it works as it should. 12V is maintained until the drivers side door opened.

[chris4851]

Just to keep you all updated I have fixed this issue. The issue had nothing to do with the wiring. The aftermarket radio that I have put in the vehicle is an integrated all in one car computer/radio head unit with a built in 50x4 amp. The PC startup and shutdown is controlled via software and the ACC 12v line. Since I have installed this software the audio now plays when the vehicle door is closed when starting.

Thanks for all your help

[chris4851]

Hey guys, not sure if this was covered before. The OS-4 have a FR (front right), FL, RR, RL audio inputs. I thought I read soemwhere that the Bose systems do not require the rear inputs to be hooked up and only the front. Is this correct? or am I way off?

[royskiies]

i just got the OS4 kit, i since my stock radio wires were cut i bought the stock connecter but i need the radio wiring guide, i have and 07 tahoe with bose and onstar