Metra Electronics GMOS-04 Manuel D’Utilisation

ALLURE 2005-07

CENTURY 2004-05

RAINIER 2004-07

RENDEZVOUS 2002-07

TERRAZA 2005-07

ESCALADE 2003-06

ESCALADE EXT 2003-06

AVALANCHE 2003-06

CAVALIER 2000-05

IMPALA 2000-05

MALIBU 2002-03

MALIBU CLASSIC 2004

MONTE CARLO 2000-05

SILVERADO 2003-06

SILVERADO CLASSIC 2007

SSR 2003-06

SUBURBAN 2003-06

TAHOE 2003-06

TRAILBLAZER 2002-07

VENTURE 2000-05

ENVOY 2002-07

SAVANA 2003-07

SIERRA 2003-06

YUKON/XL/DENALI 2003-06

H2 2003-07

H3 2006-07

ASCENDER 2003-07

ALERO 2001-04

BRAVADA 2002-05

INTRIGUE 2002

SILOUETTE 2000-04

AZTEC 2001-05

GRAND AM 2001-05

GRAND PRIX 2004-06

SUNFIRE 2000-05

9-7x 2005-07

4. Connect the Green/Purple wire to the reverse wire of the aftermarket radio.

INSTALLING THE GMOS-04

1. With all connections completed to the aftermarket radio, plug the 24 pin and 

the 12 pin connectors into the vehicles corresponding wiring harnesses.

2. Reconnect the negative battery terminal.

3. Cycle the key by turning the ignition on then back off, then back on again 

to test the radio.

TESTING THE GMOS-04

1. Turn the ignition on then the radio to verify the radio works. Check balance 

and fader controls for proper operation. If controls are backwards, check to 
see if the RCA’s are in the correct location.

2. Push the Onstar button to verify Onstar is working. the radio will shut off and 

Onstar will be heard through the left front speaker. Turn off Onstar and the 
radio will turn back on.

ONSTAR LEVEL ADJUSTMENT

To adjust the Onstar volume level find the BROWN wire that you cut on the 16 pin
harness, you will use the BROWN wire that is by itself, with no other wire with it.
Push the blue Onstar button, while the voice is speaking tap the BROWN wire to
ground. There are 4 volume settings for Onstar; once the 4th setting is reached
and the BROWN wire is tapped to ground it will automatically go back to the first
volume setting. Once the volume is set it will stay at that volume until the BROWN
wire is tapped to ground again. This can be set during installation and then left
alone. If user adjustment is desired, a momentary contact switch (sold separately)
can be added. Connect one terminal from the switch to ground and the other ter-
minal to the brown wire. The volume will change one level every time the switch
is pressed.

IMPORTANT

CONNECTIONS TO BE MADE ON THE

24 PIN GRAY HARNESS:

1. Connect the yellow wire to the radio’s 12V battery or memory wire.

2. Connect the red wire to the radio’s ignition or accessory wire.

3. Connect the black wire to the radio’s ground wire.

4. Connect the orange wire to the radio’s illumination wire. If the wire is not 

present, tape up wire.

5. Connect the orange/white wire to the radio’s dimmer wire. If the wire is not 

present, tape up wire.

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APPLICATIONS

INTERFACE COMPONENTS

CONNECTIONS TO BE MADE ON THE

14 PIN HARNESS

1. Connect the blue/white wire to the radio’s AMP turn-on wire.

2. Connect the red wire to the radio’s Igniton or accessory wire.

3. Connect the RCA cables to the radio’s RCA outputs. If no RCA outputs are

available, use the Metra line output converter part #ALO-648 (SOLD SEPARATELY).

4. The white RCA goes to the left front RCA output of the radio.

5. The gray RCA goes to the front right RCA output of the radio.

6. The green RCA goes to the left rear RCA output of the radio.

7. The purple RCA goes to the right rear RCA output of the radio.

1. Connect the Brown wire to the mute wire of the aftermarket radio..

2. Connect the Green wire to the parking brake wire of the aftermarket radio..

3. Connect the Blue/Pink wire to the VSS or speed sense wire of the aftermarket 

radio.

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• GMOS-04 Data Interface

• 14 pin harness with RCA’S

• 16 pin harness to 24 pin GM harness and 12 pin Onstar harness

WIRING UP THE GMOS-04

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