Ya, I usually will set the ground to the seat belt or the metal brackets that hold my sub enclosure. It's worked before, I'll try the sub amp tonight, and yes, I tried all 4 channels, no signal, the Signal LED doesn't even light up, none of them do. I think it's a bad connection between the positive and negative wires and the DD-1 Unit.
I'll see what's up tonight and post a movie, if anything, I hope they can RMA this for me. I'll pay shipping.