Thread: Aftermarket Radio Not Turning On

Check fuses.

I do believe, if I recall correctly, that I had to actually start the car the first time I installed an aftermarket radio in my 06 GP. I too used the GMOS-01 harness. You should NOT have to run a separate power wire either. That's about all I can tell you it's been a long time since I did this.

Yellow is constant, red is accessory power. I'm going to bet you have a bad or incorrect connection.

Your Grand Prix gets its accessory power from the LAN circuit in the car. The GMOS-01 should have accessed this if it is wired to aftermarket radio properly. You should not need to add a circuit to the fuse block.

Here are the wiring instructions for the GMOS-01 If you care to verify your wiring.
From the 16-pin harness:• Connect the Red wire to the ignition wire of the aftermarket radio• Connect the Orange/White wire to the illumination wire of the aftermarket radio. If theaftermarket radio has no illumination wire just tape off the Orange/White wire.• Connect the White wire to the left front positive speaker output of the aftermarket radio• Connect the White/Black wire to the left front negative speaker output of theaftermarket radio• Connect the Gray wire to the right front positive speaker output of the aftermarket radio• Connect the Gray/Black wire to the right front negative speaker output of theaftermarket radio• Connect the Brown wire to the mute wire of the aftermarket radio. If the aftermarketradio does not have a Mute wire, tape up the Brown wire.• Connect the Light Green wire to the parking brake wire of the aftermarketnavigation radio.• Connect the Blue/Pink wire to the VSS or speed sense wire of the aftermarketnavigation radio.• Connect the Green/Purple wire to the reverse wire of the aftermarket navigation radio.• Plug the 16-pin harness into the GMOS-013From the 24-pin harness:• Connect the Yellow wire to the radio’s 12-volt battery or memory wire.• Connect the Black wire to the radio’s ground wire.• Connect the Blue/White wire to the antenna turn on wire of the aftermarket radio.• Connect the Green wire to the radio’s left rear positive speaker output.• Connect the Green/Black wire to the radio’s left rear negative speaker output.• Connect the Purple wire to the radio’s right rear positive speaker output.• Connect the Purple/Black wire to the radio’s right rear negative speaker output.•• With all connections completed to the aftermarket radio, plug the 24- and 12-pinharnesses into the vehicles wiring harnesses.• Reconnect the negative battery terminal.• Cycle the key, by turning the ignition on for 30 seconds. Then off and onagain to test the radio.

or here is a link for the entire manual

https://www.parts-express.com/pedocs...tion-guide.pdf