GMCO Questions
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Pro
Joined: Nov 2007
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From: Cypress TX
GMCO Questions
I am getting ready to swap my factory head unit for a DDX812. I currently have the factory unit connected to 2 JL Audio amps via a SVEN4 and PXAMG. I have a 2006 BOSE without OnStar. I am not using the BOSE at all and have no plans to use it. These are following questions:
Steve
- With the GMCO I assume I use the red aux wire from the GMCO to both the DDX812 and the JL amps to provide the RAP 12v switched. The directions are pretty weak on this point and did not see the typical blue amp turn on lead. Is this correct.
- I don't understand the RCA connections with the GMCO. How does the GMCO push the chime info into the DDX812?
Steve
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From: Cypress TX
Thread Starter
Pro
Joined: Nov 2007
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From: Cypress TX
Nevermind. I guess I missed this blurb in the manual:
Do the chimes sound like a buzz or like the factory chime sound?
Steve
The aftermarket radio will perform like the factory system did. Chimes will be produced by the buzzer within the
GMCO.
Do the chimes sound like a buzz or like the factory chime sound?
Steve
Le Mans Master
Joined: Nov 2004
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From: Dyer IN
Cruise-In IX Veteran
somwhere in between, its not the same as factory, but its not a straight up buzzer either. i recommend taping over it as it can be a bit loud and the tape will quiet it, or shove it in a sock
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From: Cypress TX
Steve
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Pro
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From: Cypress TX
So I guess that means the C6 has an amplified antenna? My new head unit (DDX812) has both a amp turn on lead and power antenna/antenna amp lead. I will just hook it up to the power antenna/antenna amp lead. Thanks!
Steve
Steve
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From: North Augusta, SC
IIRC, the yellow wire coming out of the GMCO is the 'switched' wire that powers your aftermarket HU. The blue wire in the 24-pin GMCO harness that plugs into the stock 24-pin harness is supposed to connect to the 'amp turn on' coming OUT of your HU. IIRC 
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Pro
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From: Cypress TX
Will do.
Just curious why it needs to use the amp turn on lead from and not the power antenna lead from the head unit. Normally you use the amp turn on lead for devices that need to always be on regardless of head unit funtion (radio, ipod, etc) and the antenna lead only is engergized when the tuner is selected. The factory manual lists that wire as the antenna enable signal.
So back to my inital question, does the C6 use an amplified antenna or does that lead turn on other things that need to be on full time? I am going to use the amp turn on lead from my deck, I am just curious about this. Thanks!
Steve
Just curious why it needs to use the amp turn on lead from and not the power antenna lead from the head unit. Normally you use the amp turn on lead for devices that need to always be on regardless of head unit funtion (radio, ipod, etc) and the antenna lead only is engergized when the tuner is selected. The factory manual lists that wire as the antenna enable signal.
So back to my inital question, does the C6 use an amplified antenna or does that lead turn on other things that need to be on full time? I am going to use the amp turn on lead from my deck, I am just curious about this. Thanks!
Steve
Tech Contributor
Joined: May 2003
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From: North Augusta, SC
I just looked through my manuals (I was at work when I posted last night, don't tell my boss), the B3 pin that you saw was the 'antenna enable signal' coming out of the OEM radio is used to supply 12V to every other component of the sound system in the car, including the 'antenna module'. As long as you have removed the main Bose amp and both of the OEM door sub amps you should be OK hooking the blue wire up to your new HU's antenna turn on wire, if you have any of the stock amps still installed (and connected to speakers) you may get a hum or buzz when they're powered up.
I also noticed that the antenna module has another connection to the OEM radio, it's labeled 'FM composit signal' and is a yellow wire at pin A4 of the same plug. I'm not exactly sure what that would be there for.
I also noticed that the antenna module has another connection to the OEM radio, it's labeled 'FM composit signal' and is a yellow wire at pin A4 of the same plug. I'm not exactly sure what that would be there for.
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Pro
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From: Cypress TX
Steve
Drifting
Joined: Jul 2004
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From: Lucas, Texas
Yes, the antenna is a powered antenna. Check out my post in the bottom of this thread for everything you ever wanted know.
http://forums.corvetteforum.com/audi...-question.html
Jay
http://forums.corvetteforum.com/audi...-question.html
Jay
