Hi hummer owners,
I have an 2006 H3 with Monsoon, factory radio.

I want to do a new headunit, front and rear speakers, amp and sub box.

Now I have put in plenty of systems in the past but never in this new of a car or a GM for that matter.

I am under the impression that I will need a "GMOS-04" Interface.

I do not care about keeping onstar or door chime, is this interface harness required?

 

No, you dont have to use the "GMOS-04". you can just use the normal wiring harness. The local audio store advised me to be careful that if you didnt use the GMOS-04 onstar can still hear you in the mic but you cant hear them and that they were messing with the stereo and somehow it triggered onstar and onstar locked in and tried to talk but onstar never got a response so they got the cops to come with a possible break in. long story short the audio store got barricaded with cops due to human error.

 

Thanks Chris. Can anyone please provide me with link for a normal h3 wire harness? I intend to not use the GM module so I assume I will need to run my own 12volts to the new radio? Also can anyone please provide a wiring diagram for the h3 audio?

 

There are a lot of pros and cons to any specific radio harness. But we always suggest using the interface. Specifically for your model truck. The reason for this is not only based on Onstar or Chimes, but you wrote you have a monsoon System. Since this specific system has a factory sub amp that you plan on bypassing, you may have direct line feedback noise on your mid range or Hi's.

Some folks never have a problem. We did. If you plan on running a good system, spend the extra few bucks. I promise its worth it. We pulled the factory radio and faceplate and re molded a dual touch screen system in the dash. One for the head unit and one for the Nav screen. wanted to run both at the same time and keep that factory look.

Starting with the engine, we replaced the battery terminals to accept 4 gauge wiring. Next we ran the wiring through the factory grommet near the ebrake. Instead of running wiring all the way to the back of the truck, we decided to keep things centered. there is a ton of space behind the head unit. We installed the front components crossovers, a 2 farad cap, and dual screens in the space! We recommend running your own tweeter wires if you go component in the front.

We ran the hot wires down the center column and split them, placing one amp under each front seat. High amp on drivers side and low end on the passenger. we grounded the amps at the factory seat bolts. This way the only wires ran to the back are sub wires! The shorter your power wires, the quicker your power delivery and less likely a chance of a short.

I do recommend dropping the headliner an pulling the rear paneling, then installing dynamat everywhere you can. Hummers are rattle boxes. The headliner is easy, just very time consuming. Good luck and let us know what you end up installing.

 

thanks for your response. I have ordered a few things and will be getting to work shortly. I will take some pictures to document this because I havent been able to find any documentation online about this.

Going back to what you mentioned about "direct line feedback"
This feedback would occur when the installer does not hook up the factory amp to the new headunit?

 

No, the factory amp is only for the subwoofer only. The feedback comes from the wiring harness adapter designed to ommit Onstar. It makes a loop of two wires that can cause some static feedback. Many of the systems are wired to other components. Chimes, Onstar, headlight module and 4wd select panel, and passlock 3, all share a few of the same wires that report to the PCM. Some wiring harnesses have been known to cause issues, while the Pac, Metra, or Axxess adapters that utilize onstar, whether it is used or not, don't seem to carry any odd buzzes or shorts or bad PCM confusion. Remember that older model cars and truck normally run off voltage in the form of a positive or negative switching or signal3. H3's like most new version trucks often switch signals not only by voltage, but amperage and Ohms.

 

Oh Snap.....That's YOUR RIG???

Friken AMAZING!!!!