Replacing C6 head unit - No Sound! Help!
Thread Starter
Safety Car
Joined: Jan 2007
Posts: 4,295
Likes: 8
From: Issaquah WA
Replacing C6 head unit - No Sound! Help!
So I thought I'd read through all of the previous posts on installing in the C6 - but something's not right.
Installing a Kenwood DDX-7017 in place of the stock head unit (2007 2LT, non-Bose, but with amp?)
Everything appears to be hooked up correctly (I used to own my own Car Audio shop - did installations whenever needed), but I'm getting no sound whatsoever. Head Unit powers on and looks like it's playing the CD, but no output from the speakers.
My guess is
A) the stock amp isn't powering up - There didn't seem to be any connection in the GMCO harness to connect for a power trigger for the amp, only the Power Antenna - is the GMCO harness missing something?
Or
B) I shouldn't be using the low-level RCA outputs out of the Kenwood - instead, the stock amp's looking for a speaker level output?
I'll be doing a full installation later, with a bi-amp setup. But for now I just wanted to replace the head unit (waiting for better weather before tearing out the interior to run wires, insulation, etc).
What am I missing?
Installing a Kenwood DDX-7017 in place of the stock head unit (2007 2LT, non-Bose, but with amp?)
Everything appears to be hooked up correctly (I used to own my own Car Audio shop - did installations whenever needed), but I'm getting no sound whatsoever. Head Unit powers on and looks like it's playing the CD, but no output from the speakers.
My guess is
A) the stock amp isn't powering up - There didn't seem to be any connection in the GMCO harness to connect for a power trigger for the amp, only the Power Antenna - is the GMCO harness missing something?
Or
B) I shouldn't be using the low-level RCA outputs out of the Kenwood - instead, the stock amp's looking for a speaker level output?
I'll be doing a full installation later, with a bi-amp setup. But for now I just wanted to replace the head unit (waiting for better weather before tearing out the interior to run wires, insulation, etc).
What am I missing?
Thread Starter
Safety Car
Joined: Jan 2007
Posts: 4,295
Likes: 8
From: Issaquah WA
Thanks Pentavolvo!
I realized I connected the power antenna lead to the power antenna output... If that controlled the amp also, then it should only work with the tuner, and not cd... voila! That was the issue.
So I connected it to the "p.control" lead instead (which I had run to the back of the car for the future amp) and...
I discovered my $%^& Kenwood is non-functional! For some unknown reason the power amp control is triggering 12v only when the tuner is on (just like the power antenna control) and goes dead when the head unit is switched to anything else. Aaarghh! And I've waited long enough before the install so the warranty's expired!
This just bites...
So I connected it to the "p.control" lead instead (which I had run to the back of the car for the future amp) and...
I discovered my $%^& Kenwood is non-functional! For some unknown reason the power amp control is triggering 12v only when the tuner is on (just like the power antenna control) and goes dead when the head unit is switched to anything else. Aaarghh! And I've waited long enough before the install so the warranty's expired!
This just bites...
Le Mans Master
Joined: Nov 2004
Posts: 8,718
Likes: 20
From: Dyer IN
Cruise-In IX Veteran
read the manual possiably its a setting in the menu, otherwise dbl check ur wiring. worst case hook the wire to ur ignition wire and the amp will turn on and off with the car
Le Mans Master
Joined: Jun 2004
Posts: 9,289
Likes: 16
From: Skippack PA
St Jude Donor '13
The GMCO's generic non-Bose installation instruction is misleading for the C6. Even though the system isn't Bose there is still an outboard amplifier and it is expecting a low-level audio signal. So you can use the RCA outputs from your head for sound.
Sounds like by hooking in the power antenna output the head is only sending +12 when you're on radio. Instead of using the antenna to that connector use the amp trigger on the Kenwood. It will have a probably blue & white wire for 12+ output for amp triggering.
Sounds like by hooking in the power antenna output the head is only sending +12 when you're on radio. Instead of using the antenna to that connector use the amp trigger on the Kenwood. It will have a probably blue & white wire for 12+ output for amp triggering.
Thread Starter
Safety Car
Joined: Jan 2007
Posts: 4,295
Likes: 8
From: Issaquah WA
Thanks guys!
I did double check the wiring (pretty sure that wasn't it, but just in case), and it's definitely the unit.
Both the Power Antenna and the P.Control output of the head unit put out +12V when the tuner is switched on, but then go to 0V when the unit is on any other source. Called Kenwood, and there's nothing configurable to resolve this. It's a very odd defect, but there's not much in the instal lthat could cause this.
For now I've connected the power antenna/amplifier wire in the stock harness to the switched 12v out of the GMCO. Definitely not ideal, but at least I can put the dash back together and drive the car for now. I guess the head unit will go in for repair when I'm ready to tear out the interior for the full install.
There's a definite whine from the amp when the stereo's shut off and the cars running - no signal out of the head unit, and power switched off, so there's bound to be some noise picked up. Guess I'll leave it in standby mode when I'm not listening to tunes.
I did double check the wiring (pretty sure that wasn't it, but just in case), and it's definitely the unit.
Both the Power Antenna and the P.Control output of the head unit put out +12V when the tuner is switched on, but then go to 0V when the unit is on any other source. Called Kenwood, and there's nothing configurable to resolve this. It's a very odd defect, but there's not much in the instal lthat could cause this.
For now I've connected the power antenna/amplifier wire in the stock harness to the switched 12v out of the GMCO. Definitely not ideal, but at least I can put the dash back together and drive the car for now. I guess the head unit will go in for repair when I'm ready to tear out the interior for the full install.
There's a definite whine from the amp when the stereo's shut off and the cars running - no signal out of the head unit, and power switched off, so there's bound to be some noise picked up. Guess I'll leave it in standby mode when I'm not listening to tunes.
Intermediate
Joined: May 2008
Posts: 46
Likes: 1
From: Ayer MA
P. Control output goes to which harness wire?
I hooked up my DNX9140, and no sound at all. I looks like I need to use the HU's P. Control output to turn on the Bose amp, but which harness wire turns on the amp? There is a white wire in the radio harness (connector 1, pin B3) that goes to the amp...it's labelled Antenna Enable Signal in the Vette shop manual. Is that it?
Tech Contributor
Joined: May 2003
Posts: 7,035
Likes: 134
From: North Augusta, SC
I hooked up my DNX9140, and no sound at all. I looks like I need to use the HU's P. Control output to turn on the Bose amp, but which harness wire turns on the amp? There is a white wire in the radio harness (connector 1, pin B3) that goes to the amp...it's labelled Antenna Enable Signal in the Vette shop manual. Is that it?
Most interface adapters have a blue wire that you need to connect the blue/white HU wire to, but connecting it directly to B3 also works.
Some adapters seem to only have a 5v output, if the instructions show a relay you may have to connect the blue/white on both sides of the interface harness.
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