Help! Another GMOS-04 horror story – AVIC D3 install

OneFstVette · 03-15-2008, 11:57 PM

As many others on this forum I had to learn the hard way that GMOS is a POS. Anyway, I followed the instructions that came with the GMOS, plugged everything in and everything powers up and seems to work; however, there is no sound coming from the speakers! I thought it was the same problem as someone else had, so I went to radio shack and got the relay. Connected everything and still no sound. I am pretty desperate at this point. Please help!

I will try to put as many details as I can think of….
First of, mine is a 05 1SB package – bose, no navi, no onstar.

So first question about the relay: seems like there is only voltage at the pin which is connected to battery, is that my problem right there? I connected GMOS to pin 85, 30 is going to the vehicle, 86 to ground, and 87 to battery power – this is the only one with any voltage.
My D3 seems to stay on even when the car is completely shut off. Also I did the bypass by moving the Mute wire up in the harness and connecting it to the ground wires, I also connected the parking brake wire to the ground wires.
I tested to make sure there is power to the ACC and system remote control wires going to the D3.

Regarding the instructions for GMOS:
1. It said to cut the brown loop on the 16 pin harness and tape it up – I did that

On the 24 pin gray harness:
2. I connected the orange wire to the ILL wire going to the D3
3. I did not connect the orange/white wire to anything since there was no corresponding wires on D3

On the 14 pin harness :
4. I assumed the red RCA cables correspond to the right channels and white correspond to left channes, I assume either way I connect them, I should still hear something
5. The instructions say to connect the brown wire to the mute wire on the D3, I skipped that step since I connected the mute wire to ground as part of the bypass
6. Also I skipped connecting the Green wire to the parking brake wire for the same reasons as above
7. I connected the VSS wires from the GMOS to the D3
8. I connected the reverse wire from the GMOS to the D3

Those are only a few places I could have screwed up, I will try to think of more. Any help would be greatly appreciated.
Thanks!

pentavolvo · 03-16-2008, 01:28 AM

my understanding is that relay is when the unit wont turn on

it sounds to me like you arent triggering the factory amp turn on

i must be the only one who has done like 5 gmos installs with not one problem

OneFstVette · 03-16-2008, 02:31 PM

I tired supplying the factory amp wire with battery power and I get a 'knocking' sounds out of the speakers. I also tried connecting it directly with the amp wire on the D3 with the same result. Any ideas what is happening? What kind of voltage is needed to trigger the factory amps?
Thanks

pentavolvo · 03-16-2008, 04:42 PM

ok if you hooked the factory amp wire to battery power and you heard it pop/knock on and you power up the radio then do you get sound. because it only takes 12 volts to get that amp on.

OneFstVette · 03-17-2008, 10:42 PM

ok so I had a friend who installs car stereos for a living looked at my wiring, he said that it looks like I have a defective harness! I am done with GMOS, can anyone suggest a better harness for bose and no onstar? Also do you think Crutchfield will take this POS back since I have cut some wires already?
Thanks guys..

gbrand07vette · 03-17-2008, 10:52 PM

I had the exact same problem. Messed with it for days then finally took it in to an installer who replaced the gmos pos with a peripheral gmco and we were in business in less than 15 minutes. Added a couple of ground loop isolators to clean it up and it was good to go.

OneFstVette · 03-17-2008, 11:05 PM

Quote:

Originally Posted by gbrand07vette

I had the exact same problem. Messed with it for days then finally took it in to an installer who replaced the gmos pos with a peripheral gmco and we were in business in less than 15 minutes. Added a couple of ground loop isolators to clean it up and it was good to go.

Thanks, did you get your money back for the gmos? Also do you have a direct link to where I can get the correct GMCO? seems like the ones I've seen online don't support premium bose system?
Thanks again!

gbrand07vette · 03-20-2008, 12:42 AM

Quote:

Originally Posted by OneFstVette

Thanks, did you get your money back for the gmos? Also do you have a direct link to where I can get the correct GMCO? seems like the ones I've seen online don't support premium bose system?
Thanks again!

Here is the link to Peripheral's website. http://www.peripheralelectronics.com/
You should be able to find the model specific to bose system. GMCO is only for non bose. The bose version is also listed in the sticky on this site and referenced in many threads.