hey guys looking to do a double din install, i ahve a 2003 hummer h2 with facotry bose sound system, and rear seat entertainment
what i want and need is : steering wheel button control and whatever else easily integrates into my hummer

what would i be nice: i dont use onstar but i think the mic on the roof for calling is for onstar, can i get that integrated into my stereo and use it for handsfree calling?

for these two sitatuins should i use pac, axxess or a diff brand?

thx

 

On my 2003 I read a lot of reviews and went with the Metra brand adapters as the PAC ones seemed to get worse reviews. That being said, I'm as happy as can be. Everything in mine is still going through the factory Bose amp and speakers and it is sounds excellent in my opinion.

You will need an install kit. The catch is with retaining the stock Bose amp and retaining use of the steering wheel controls. The adapter harnesses and electronics for those are not terribly cheap. You will need a few items in addition to the aftermarket stereo itself. These are the bits I went with.

Main adapter harness - Metra GMOS-04 - this adapts the wiring, retains the vehicle chimes, and interfaces with the Bose amp.

Steering wheel controls interface - Metra ASWC-1 - this allows your aftermarket stereo to use the factory steering wheel controls. This is technically optional, the steering wheel controls just would not work if you skip this.

Antenna adapter - needed for most GM vehicles since GM insists on putting a stupid tiny antenna connector on the factory stereos.

On the installation mounting kit. I am not fond of one aspect of the Metra one I got but others might be the same way. The way the side pieces attach to the front ring has come loose leaving my stereo sagging and unsecure on the right side. Now I need to pull the whole dash and console back apart to fix it. I know exactly where and what the problem is though and I guess the kit would be fine but GLUE the left and right pieces to the front piece before you use it. Also another tip. When you have the factory stereo out and whatnot, you can use a dremel and remove a small amount of the dash plastic on the upper left behind the 4WD switches and there is a nice pocket of space there where you can shove some of the extra wiring and the adapters for the steering and system adapters.

On a 2003 there is a 99.9% chance that prior owners never took advantage of the Onstar digital upgrade a number of years back. This means the old analog Onstar system is useless garbage in your H2. You can find what is needed to upgrade it to the newer digital Onstar system, remove it and repurpose bits of it, or just yank its fuse and leave it there. There is a pocket that was available to replace the Onstar module in the dash giving you extra storage but those are now near impossible to find. Just a year and a half ago I found a dealership that had some and posted about it on here but I think I've read that others can no longer find them and that dealer sold out of them. Plenty of other options too. Can just remove it and get a piece of black automotive carpet and line the pocket. Put something else there like off road light switches, etc.

On my install, I do not like the way aftermarket stereo microphones look sticking out somewhere, nor do I think aftermarket head units built in GPS antennas work well unless mounted on the roof which I also dont like. When I pulled the Onstar out I rerouted its GPS antenna cable and microphone cable to the back of the stereo pocket and used those. The built in Garmin GPS in my Kenwood works excellent using that factory Onstar roof GPS antenna. The factory Onstar mic already in the headliner works great for the built in bluetooth phone capabilities on the Kenwood as well. I had to get an adapter for the GPS antenna cable end and had to just cut and splice the mic wire connector on.

Oh and one other thing... 2003 was the only year that had the AM/FM antenna on the roof (passenger side). All other years have the AM/FM antenna on the front fender side vent. If your AM/FM antenna ever gets damaged there is a Metra one of those that also can be mounted in the same hole and works great.

In regards to the Onstar mic and GPS antennas....
On the plugs that connect to the back of the Onstar module.
The white 12 pin plug has the mic wires. Grey is the center (signal), bare wire is the drain (ground). These are pins 9 and 10 on the 12 pin plug. If you look close the plug probably has some tiny numbers on it somewhere indicating which they are. 9 and 10 are the two middle pins on the flat side without the release clip. So if you cut a 1/8" mono plug like the Kenwood uses and strip the wires to extend it to your stereo the grey would go to the center pin wire on the plug.... Also on my Kenwood, when in the phone screen settings, I turned the mic gain up to max and it works perfect.

There are two antennas connected to the back of the Onstar module. One has a threaded connection. That is for cellular communication. The other is the GPS antenna. I do not remember offhand what the factory connector is. You can get short adapter cables to extend it and convert it to the GT5 connector that Kenwood uses (easiest). I re-routed it to reach the Kenwood, cut the end off and put on a GT5 connector - you need a specialized crimper to crimp the tiny center conductor on those. I'm really not sure but the factory cable might be a Fakra connector.... This is the sort of adapter cable you can get - https://www.ebay.com/itm/133140149551But again, I'm not sure what the factory end is. I know my Kenwood uses a GT5 connector for its end though. In the underhood fuse box, pull and leave out the VCIM (vehicle communication interface model) fuse which is for the Onstar module. It is useless anyways and no need leaving it powered and they are known to kill batteries since the module even, when not active or subscribed, is still trying to locate cell towers and satellite signals.

This thread - https://www.hummerforums.com/forum/h...66/#post341996 is where I gave more info on removing the Onstar module.

 

wow thank you so much!!
i wanted to ask tho, is the onstar mic high quality or better to use the provided mic?

thx

 

Seems to be very high quality. That being said, on my Kenwood I did need to turn the mic gain setting up. Talk to my wife on it a lot and she says I'm clear as can be using it.

 

great thanks! and when i splice the onstar mic to make it a 3.5mm jack, wont i need 3 wires coming from the onstar wires to correctly solder with the 3.5mm?
or just doing the two wires is fine?

thx

 

The 3.5mm mic jack is mono so only two wires needed....

 

Great thanks! I’m running a pioneer nex double din deck and noticed that the audio quality is clear and good around 3/4 volume but when I go max, the bass and audio distorts. I played with the GMOS screw and It’s still bad unless I obviously lower the max to too low.

Is this normal? Like are my factory Bose just getting old? Or must be something wire related

thx

 

nvm thanks for all your help man! got it working great!

 

Thanks for a great write up! Does this use the existing amp or doe you think one should be added?