using my existing BTA8100 with new stereo
I have a BTA8100 connected to the factory stereo in my 2004 Silverado using the FAST 2003/BTAH system. I will be installing a Pioneer AVH-x2500bt using the Metra GMRC-01 adapter. Will I be able to just keep the FAST harness connected between the GM harness and the Metra harness? Is there a better way to connect the tube to the Pioneer? I know it has additional outputs that the GM stereo doesn't have but the sub is in place and the BTAH harness gets up behind the radio well and it works and sounds fine like it is now and I would be happy if it is the same with the new stereo. Will it be that simple?
Also, the only issue I have now is the sub doesn't stay on when I turn the key off and the stereo stays on with the Retained Accessory Power. It's not a huge deal but would be nice if I am going in back there to correct that if I can easily. thanks for any advice here.