installing aftermarket HU...need to keep onstar
 

Ok, let me run this by you guys:

I'm going to install my HU...and all speakers will be amped externally. (none powered by the HU itself.

So, because it SEEMS that the GMOS-LAN-03 ties into the front speakers (which would be powered by the HU....I'm thinking that I'll hook that wire up to my rear speakers (which I was going to leave disconnected anyway) so the onstar SHOULD work through those...while my front speakers will be amped.

I'm hoping onstar will still be able to mute things.

I'm using the 03 because I have the low end factory stereo.

Thoughts?

I'm sure if you have onstar you have to use the 04 to keep it working. You can still use the preouts on the HU to run all the speakers

I have a 2008 with the low end stereo. Early this week I purchased an 03 unit from Crutchfield for my Onstar. That is the unit they said to use without the Pioneer radio. I figure they know what there talking about.

From the Metra website... I have a new HU in my Saturn Sky with onstar, everything works well except the turn single chime is a little loud.


Description

GM non - amplified interface harness. Retains chimes and accessory. Works with or without onstar and provides navigation wires. Click on part for more details


Product Specifications

-For 2006-07 Chevy HHR, Pontiac Solstice, Saturn Sky with non-amplified audio systems
-Retains Onstar with adjustable volume output
-Retains chimes with adjustable level output
-Retains RAP feature
-Output for audible turn signal sound
-Navigation outputs now included
-USB update interface compatible
The GMOS-LAN-03 interface is designed to allow the user to replace the OEM radio with an aftermarket unit in non-amplified 2006-07 Chevrolet HHR, Pontiac Solstice, and Saturn Sky that use the new GMLAN data bus system and retains full functionality of the Onstar system as well as all safety and warning chimes. The GMOS-LAN-03 will also retain the retained accessory power convenience features. This interface has the capability of adjusting chime and Onstar volumes as well. In addition to these features, the GMOS-LAN-03 now has the required outputs for the installation of a navigation radio.

I understand what it does...but I think they're assuming that your new HU will be powering your front speakers.

My problem is that I won't be powering any speakers with my new HU. The GMOS has no way of putting the onstar audio through my RCA outs that go back to the amplifiers.

Now, the 04 DOES do this...but I'm wondering if it won't fit for some reason...like the car-side connector is different when you have the upgraded sound.

I believe these adapters are basically for only replacing the HU and that's it. The question is how it works when using on-factory external amplifiers.

I'm thinking I can just use the rear speakers for the onstar...

Update, I've found out that you do have a different car-side harness (connector) if you have the premium radio...so with the base factory radio, you cannot use the 04.

So, has anyone hooked up the GMOS-LAN-03 to a dedicated speaker for chimes and onstar? That's what I'm going to do...but I'm thinking I'm going to have to switch wires around BEHIND the 03...so it's connected to the rear doors.

Have I lost everyone yet?

I spoke with a Crutchfield Rep the other day and asked him this exact question. He said the way to go was to hook up a small speaker to the radios left front speaker, which plays the Onstar. He said others have successfully done this and it was really my only choice if I wanted to keep Onstar. When I install my Amp that's what i'm going to do.

where about do you get the part to put aftermarket stereo in and keep on-star, door chimes etc. working? and how much do they run?

i have a 08 HHR LT with 7 speaker pionner currently

Crutchfield sells them for $125 I think, 1/2 off that if you purchase your HU there.

I'm going to do just that...except that speaker is going to be the one already in my rear door. I'm going to "jump" the front speaker leads to the rear speaker leads and go from there.