Help! Slow Battery Discharge

Mopar Friends
Thanks for all the suggestions. Here's an update. Used my DVM across the ground cable and negative battery post. Have a 13.1 VDC draw. The car is a radio and heater delete so it only has 4 fuses. The owner before me added a separate fused terminal block with 5 fuses. I have pulled all fuses and still have the draw. I have disconnected the alternator and still a draw. Today I put my battery disconnect back on but I would like to fix this issue. I will trace out the wires from the previous owner terminal block. He added a Holley blue pump, an MSD 6AL and MSD retard box. The car has no hood or trunk light. 'm guessing it must be something outside of the fused circuits. It has done this since I purchase it 6 years ago. I will continue to post my results. Thanks for all the help.

Everyone may have missed this and I may have misread but if you are on volts scale and you are reading 13 volts between your negative battery post and vehicle ground... you have a super ground problem and more like a very poor grnd, almost a open circiut. THAT needs to be resolved first.