Help wiring GMOS-04 in Grand Am

[funkman262]

Hey guys, I'm wanting to install a Pioneer FH-X700BT into a 2003 Grand Am GT, and in order to keep the chimes I'm also wiring in a GMOS-04. I've never installed a stereo before, and I think I understand what I need to do, but I would like to verify before going ahead with the install.

The radio harness has 2 each white (front-left), gray (front-right), green (rear-left), and violet (rear-right). It also has a red (ignition switch), black (ground), yellow (12 memory), and blue/white (amp). The 16-pin harness on the GMOS-04 has all of those but the yellow and black which are on the 24-pin harness.

So there's a few things I'm not positive on. The 16-pin harness has two red wires, and then another one coming from the 12-pin harness for ASWC (but I don't have radio control on my steering wheel). Do I just connect the two red wires from the 16-pin to the red wire from the radio harness? For the ground, I believe I'm supposed to connect the blacks from the 24-pin and radio harnesses, then screw that into the metal frame under the dash.

GMOS-4

View attachment 26540117

16-pin

View attachment 26540118

View attachment 26540119

That loose black/yellow wire is for Onstar volume control, which I don't have.

24-pin

View attachment 26540120

Top-to-bottom loose wires: black, yellow, orange/white, orange. Do I need to do anything with the orange illumination/dimmer wires if they're not on the aftermarket radio harness?

View attachment 26540121

There's the other red wire I was asking about. I also don't know what that plug is for, but I'm assuming it doesn't apply to my system.

Radio harness

View attachment 26540122

Is there anything else I'm missing? Do I need to hardwire into anything else in the car? Am I supposed to cut any wires? I know I sound completely clueless, but I actually love to DIY and learn as I go. Thanks for reading //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

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[1loudbuick 10+ year member]

It sounds like you need to do more research on cd player installs it isnt somethin you want to try to wing or have someone blindly tell you what to do without seeing it in person. Im confused just by the description and pics on what your asking and ive installed 25+ cd players and alot with the interfaces. Mabe your close to a forum member that can help you out where are you located?

 

[funkman262]

I've been reading install articles and watching videos, and it seems pretty straightforward, but I think it's the GMOS-04 that's throwing me off (couldn't find anything specific to installing these). I can match up all of the wires by color from the aftermarket radio harness to the GMOS. From what I've seen, that's all that's typically required. But then there's all the extra wires on the GMOS for stuff that I don't have, like Onstar, so I was just verifying that I don't need to mess with any of those additional loose wires. And I'm in Tampa, FL.

 

[dhall615 10+ year member]

I did a similar install on my impala. The paperwork that came with my HU and instructions that came with the wiring kit were straight forward. The HU should tell you exactly what each wire does and so should the instructions in the wiring kit. Then all you have to do is match the wires.

 

[1loudbuick 10+ year member]

As long as your power and grounds are properly hooked up you should be able to safely test it out and see for yourself if there needed

 

[funkman262]

I did a similar install on my impala. The paperwork that came with my HU and instructions that came with the wiring kit were straight forward. The HU should tell you exactly what each wire does and so should the instructions in the wiring kit. Then all you have to do is match the wires.

Thanks. The wiring from the radio harness is straightforward as you said, but GMOS is a bit confusing. My main question would be about the red wires since the GMOS has 3 of them. I'm assuming I need to connect both of the red ones from the 16-pin harness of the GMOS to the red on the radio harness, but I have no clue what the third one on the GMOS is for.

As long as your power and grounds are properly hooked up you should be able to safely test it out and see for yourself if there needed

I was planning on doing that, but I needed to figure out the whole red-wire issue before I start anything.

Sorry if I'm being confusing. I tried to lay it all out in the pics so that you can see the loose wires that I'm asking about, but let me know if there's anything else I should show to give you a better idea of what I'm working with. Thanks again.

 

[dhall615 10+ year member]

You will have a red for the radio and red for the unit to keep the door chimes. Im not sure about the third. The GMOS not say what they are?

 

[robert420 10+ year member]

does the radio you want to install have a diagram on the back of it?

 

[funkman262]

Well I went ahead and connected all of the radio wires to the corresponding colored wires on the GMOS, disconnected the car battery, drilled a hole into the metal frame behind the radio to ground the black wires, plugged it all in, connected the battery, and it all works great. I still don't know what the other red wire was for but it may only be required for Onstar or something. I checked the fade, balance, and most of the features of the new stereo and it's all working properly. I think I just convinced myself that it was harder than it actually was so I let all the extra wires intimidate me. Thanks again for all the help guys.