Volkswagen Forum - VW Forums for Volkwagen enthusiasts - Unplugged Wires Behind Aftermarket Radio Control Central Locking???

I recently purchased a 2000 Cabrio in which the central locking system does not work. I do not think it is the vacuum pump that is the problem as there is power going to the pump and the trunk release works so I tend to think it is electrical. I have taken the interior panels apart to trace the wiring and this is what I have found. One set of wires wrapped in black tape running from the fuse box to the central locking unit in the trunk has power and another set running right next to that set has no power. I have traced the set without power from the trunk to the radio harness thinking I would find a cut wire or something but instead I found 3 plugs running to the back of the radio. 2 black plugs that have all of the stereo wires which are plugged into the back of the aftermarket radio and a blue plug with the wires that had no power running to it which was unplugged and just hanging there. I have searched the internet and cant find too much info on that hanging blue plug except that it looks like it plugged into the stock radio for the anti theft system. Could this be the reason that the locks have no power and the alarm does not work? Also if this is the case how do
I fix this? Thank you sooooo much in advance!