Help pls... Nexus7 + GMOS-04 + Headunit replacement
 

Hi all gurus,

I own 2006 Hummer H3 with monsoon system.

I am planning to replace the stock headunit and replace it by Nexus 7.

So I've ordered Axxess GMOS-04 harness. (LINK)

I've connected all the wires as per the manual and got some idea from this youtube video ( ). But now I am stuck with few questions/confusions (sorry I am not electrical guy).

From the 24-pin harness (which will connect to factory harness), I am left with:
1 Yellow - 12 volt battery/constant (12v+)
1 Black - Ground

From the 16-pin harness (which will connect to GMOS-04 adapter), I am left with:
2 Red - 12 volt ignition/switched (12v+)
1 Blue/White - AMP turn on (12v+)

So, my questions are:
1. Which wire/s should I connect to cigarette lighter adapter (which will supply power to the tablet, I want to supply power only when I turn on the keys), Yellow / 1 Red / 2 Red ???
2. Should I connect Blue/White wire to the power supply wire (answer from 1) so that it will turn on the amp as soon as I turn on the keys???
3. How the GMOS-04 will retain the RAP feature in my case ???

Here is the pic which is part of my complete set up:

Attachment 8451

I bought my H3 (pre-owned) with the GMOS-04 already installed. I have learned it was needed because of the new Kenwood cd/dvd player that was installed in place of the original radio.
Be aware that the GMOS - 04 produces an annoying noise/whistle when you turn the radio on, and it seems impossible to fix that problem. Maybe there is a better interface out there.

Thanks h3puertorico for the heads up. I've already orders ground loop noise isolator to get rid of all the possible noises.

Please! As soon as you install them, do tell me if those "noise isolators" work.

I'll do for sure but you'll have to wait till weekend.

Nexus
 

If your just routing power to the tablet you can snip the cigarette lighter adapter off and wire the ground and hot to that cable directly. Same goes for the speaker outs. Plug a headphone jack into the nexus audio out and snip the ends and route that for sound should be all it takes. I don't really know if you can do a remote turn on without the tablet having an actual remote turn on switch embedded. You should be able to route an accessory switch to it or possibly grab power from the cigarette lighter. The noise coming from the gmos has a blue plastic screw on one side that an be used to turn down the chime noises also.

Thanks cjyoung111... I kinda solved the wiring part.
When I join the speaker wires from GMOS adapter to tablet's audio output, I get the sound, but it's very slow, you can say 1/4 of original stock system.
I've rotate the blue screw on GMOS box all the way clockwise, but no improvement.

Any idea why is that...?

I've googled for other's install and they are using DAC in between speaker wires and tablet. I've ordered one to see if it help.

The DAC "digital to analog" converter should help with the low sound / output of the audio. Just re read the manual from my GMOS and it states that the blue screw is for adjusting the volume for vehicle chimes. Don't know why it's not working however the GMOS I have came from "Metra" and although I do like the harness they are very cheaply made. You may have a faulty volume switch on the actual GMOS unit. When the chimes sound in my vehicle they are emitted from the left front driver side speaker. Id say get a 4 channel amp after getting the DAC and see if you could boost the sound even more. I cut put my door panels and put 6x9 speakers in each door. If you want loud the 6x9 are the way to go and not very expensive either.

I already have monsoon system which means I've amp in my H3. Do you still believe I need another amp...?

I've got 4 of Polk DB 6.5 and installed in front door, still need to install in rear ones. I must tell you it made huge difference. The lows and highs are awesome. It made everything vibrate.

I can check the result after installing the DAC, otherwise I'll need to check with Metra guys on this Blue screw.

I had 6.5 in my H3 before just to make it easy on the swap but the jump to the 6x9 made a huge difference in volume. I'd say twice as loud just by upgrading the speakers from 6.5 to 6x9. Second amplifier? This is really dependent on the amount of RMS wattage of your speakers. For instance...the Polk 6.5 come in wattages of 15, 25, 50, all the way up to 100. It really depends on what you bought I like to stay in the 50 watt range and I don't need much to really drive them. Kind of like having a hot rod with an elderly citizen behind the wheel if your underpowered. I don't know which RMS watt speakers you have but if you say it's vibrating things your pretty much spot on. I'd shy away from the amp in that case and get a new head unit like a double din that has good wattage also. That will help as well. I have a Pioneer AVH-X3600. It plays DVDS and gives out 40 watts per channel. I got it off Amazon too for like 245.00. It made a big difference in overall volume and sound quality in my H3.