Haplo5

Has anyone had any issues using a Metra GMOS-04 to install an aftermarket headunit in a Bose equiped 05?

I determind it was not turning on the Bose amp so i bypased the amp turn on wires (so they go directly from the factory harness to the Kenwood). This seemed to work but, the audio level is really not that loud. If I put the car in Acc mode and open the door (so the chime comes on) the stereo sound is about 10 times louder (the way it should be under normal conditions).

I thought maybe it was a bad unit so I had the metra replace it but, I'm still having the same issues.

Additionally, If I adjust the line in level on the GMOS-04 (while the car is running) I can get it to a half way desent level. but once I turn the car off and back on again, It's not giving the same DB's as it was before shutting the car off. This isn't good because I have to dismantle the console to get to the Metra.

Any help would be greatly appreciated, I really need my heavy metal to keep me calm behind the wheel (LOL)

EVIL_C5

i have that adapter in my 06 silverado. the one thing i read is to make sure to center out all of your settings for treble and bass before unhooking the factory radio. mone works like a champ in my truck and the sound quality isnt too bad at all.

Haplo5

I finally got this fixed...... ....I thought I'd add the solution here incase someone else is having the same issue.

After speaking with Metra about the problem, I was informed that the GMOS-04 does not have the software installed to replace the in dash 6 disk changer with an aftermarket head unit.

They did give me a work around thought.

1) Hookup the factory radio (turn the car on and make sure it’s working).

2) Set the Bass Mid And Treble to 0

3)Turn the car off

4) Remove the factory radio

5) Install a relay on the blue wire with a white stripe on the Car side of the GMOS-04 to increase the current, which will in turn, increase the voltage. (Grab the power for the relay from the constant wire)

6) Install the GMOS-04 and Aftermarket Head Unit

7) This step is not required (but it is helpful): Before you put everything back in place, Put the Car in ACC mode (so you can hear the radio with out starting the car, Open the door (this causes a chime), Use a small screwdriver to adjust the sound level of the chime (It's the small blue one on the side of the GMOS-04)

whosnextdcl

Both of you have provided a lot of useful tips that can help me with my GMOS-04. Hopefully you can help me just a bit more. I have an 06' Silverado with the 6-Disc Changer, Bose and OnStar.

Since the GM and Metra set-ups are so sensitive, should I disconnect the battery or leave it connected when I disconnect the factory radio?
Along with adjusting the Bass and Trebble to midway, do I need to adjust the Volume?
Should the radio be on or off after I make those adjustments?

I'm also dealing with alternator noise coming through the speakers that fluctuates with my truck's RPMs. I can't imagine there being a grounding issue. It doesn't come through the stock radio, but it's the same sounding noise I hear from under the hood when I start the engine. Did either of you run into that problem?

Thank you in advance for any help you can provide.