Hello everyone, I was looking for a little help on the GMOS-01 adapter for after market stereos. I have an 2001 LS without onstar. I bought an aftermarket stereo a while back and got it installed no problem, and then about a month after having it it was taken out of my car. Went and bought another a couple weeks ago and it's pretty much just a better version of the one I have same wiring harness and everything. Got it all hooked up and tested out and nothing. No power to the unit no door chimes absolutely nothing. Don't understand as it worked fine with the other unit and the new uses the same harness, all I did was plug in the harness that was already in the car. Any help as to why this could happen I would appreciate it.