I’ve got an 02 Ram with a 5.9 Cummins and 5 speed manual trans. I just rebuilt and reinstalled my starter. When I turned the key I had no power to the dash. All of the fuses under the hood checked good. Then I put some battery post shims on the negative terminals because the cable clamps were still loose after max tightening. Now, some of the time, when I turn the key, the dash lights up, but when I try to engage the starter, everything goes dark again.

Where red do I need to start looking for the problem?!?!