Im installing a Pioneer avic x930bt into my 04 tahoe. Ive done installs before however this time im having to use the Axxess gmos-04 interface and this is where im confused. The manual for the stereo says to ground the black wire, however the manual for the interface is saying to just connect the ground wires. I decided to just connect the ground wires as this is how the pervious owner had the old head unit installed. Eerything was working fine for about 10 minutes then my battery went dead. Im assuming i need to ground the stereo wire instead but wanted to get another opinion before i messed with it. If i do need to ground the stereo wire do i just leave the ground wire on the interface capped off or ground that as well? Also, there are 2 ignition switch wires on the interface. Do i connect both of those wires to the ignition switch wire on the stereo? As far as i know all other wires are connected correctly.