It is not that I will not try this. I am just saying what has happened so far. After 7:00p.m. it is pointless to attempt anything. I am messing with this car outside in 4 degree weather.

No heat and no sunlight makes for very difficult working conditions if you get my drift.

It was already suggested at least TWICE to check the amp turn-on lead with a meter up to this point. KTBoom2006 has been tasked with this and to this point has either been unable or unwilling to do this. It has also been suggested that fuses be checked at least THREE times now, and this was verified as done. The question still keeps being asked! It was also suggested at least TWICE that KTBoom2006 attempt to manually trigger on the amp. When these things actually start to happen, maybe it will be possible to figure out what is wrong. In the meantime, we are doing nothing but running in circles, repeating each others posts and WASTING A LOT OF TIME.

agreed the amp turn on trigger needs to be tried, just asking install supervisors for help here on my end to see if the amp turn on issue was a common problem on the OS09, which it DOES appear to be, which would lead me to beleive this is going to most likely to be the solution to no audio *shrug* im not tryin to jump outside of your scope of process of elimination, simply stating from a RETAILER/INSTALLER standpoint that the 09 is a weak module, at best

We are going to try that tomorrow maybe. Depending on if our Daughter is feeling good. With the meter, I have to get it from my brother in law in order to test it. I usually don't get home until 6 which only gives enough time to to try one thing before it gets dark out. So yes it takes us some time to test the things everyone is suggesting, but we are trying them. We know the fuses aren't blown, and we know that the cd player works. So we are now going to try to jump the amp next. Sorry

And for the ppl who are going to ask their installers, Thank you for taking the time to do so.

I would like to see this issue resolved and not given up on. I spent alot of time trying to figure it out before giving up. But I know on my side it had nothing to do with fuses because I would put in the stock radio and everything was good. I know the GMOS is going to have to be altered in some way, wires added or to bypass something in order for it to work. Its sucks because its $99 and doesnt work.

Thank you for being on my side that there aren't any fuse problems. And it does suck to spend $110 all together with taxes and still not work. Did you try running a remote wire to the amp?

This is clearly not the issue. The problem is that (with no offence to other members here), too many comments are being interjected by individuals who do not have enough knowledge about the OEM side of this. These were checked early on and found not to be a problem. The fact that reinstallation of your OEM deck proved to work is definitive evidence that this isn't the problem.

If you have connected the remote turn on wire from the HU directly to pin A3 of the 32 pin Dock-N-Lock without success, running a wire directly to the amp will not yield any different result.

This is NOT a permanent fix anyway, since you will likely lose the function of your OnStar (and perhaps other functions). As previously mentioned by your wife, when the OnStar button is pressed, the radio turns off (which seems like a normal function of the module). When this happens, your amp turn-on signal will also drop and you will lose audio function for OnStar. The reason the amp turn-on is controlled via the module and not directly by wiring the HU output to the amp is to retain this function. If you do this, you will likely also lose any warning chimes you would normally hear whenever your HU is powered off.

After you measure the voltage on the output of the HU amp turn-on wire, ALSO measure the voltage at pin A3 of the Dock-N-Lock. If you have +12V at the output of the HU, you should also see this at pin A3. There are OTHER causes which can prevent the amp from turning on apart from the amp turn-on signal. One step at a time though

Thank you, I will let my husband read this when I get home and see what to do from there. Right now we have a bad ice storm going through, so probably won't be able to do it tonight. This is where a large garage would be handy.

Ended up being a bad module. Was getting 11.x volts with vehicle off and 13.44 volts with car running off of the stereo. Tested inside the module directly from the 10 pin connector was still getting 11.x volts non-running/13.x volts running. Tested the 32 pin connector at the module and no good. 0.00 volts although there are two remote turn on wires coming out of the module. Both are bluish grey. First wire is giving volts second does not.

Jumped the remote turn on directly from the h/u to the 2nd bluish grey remote turn on coming out of the gmos-09 module. Finally get sound with out any chimes or OnStar prompt like ddalder stated. Although I hooked it directly to Pin A3 before and got nothing unless I had a bad connection on it on that attemp.


This sucks. We purchased this module at a custom audio shop 2 hours away because we were in the area and they happened to have it in stock.

What'* important is that you have been able to narrow down the cause. I'm sure you're already on this, but you might try the manufacturer directly to see about warranty. Also, see what the shop says. Perhaps you can even ship it to them.

What you found makes a lot of sense. Now it'* just a case of resolution.

Great work