65 Breezeway charging system issues. Please help!!!
 

I just bought a 1965 Monterey Breezeway and it's having some charging system issues. I have just replaced the alternator and voltage regulator. I very carefully checked all of the wiring from the two to make sure there were no bare wires grounding out. The car only starts when jumped. If you pull the negative side of the charge off the battery the car dies instantly leading me to believe that it is something to do with the alternator or power from alternator to the battery? The alternator was tested and is kicking it the appropriate amps. The battery was tested and is decent or has about another year or two of life in it. We are going to try changing out the solenoid tomorrow morning since the charge from the alternator to the battery runs through the solenoid. I'm stumped and new to car mechanics and restoring older cars. Any suggestions of what else could be going on? Thank you so much!!