Classic/Antique Car Repair: 1948 Plymouth 2 door sedan, volt system, hot wire

Question
6 volt positive ground charging system. I have a new regulator, new battery and have had the generator checked. I polarized the generator and run an extra ground wire for good connection. It starts and runs good all day but if I use my headlights it doesn't want to restart when I shut it off. I guess basically my battery is not charging back. I have tested taking the hot wire off the battery and it still runs. what else is there to check to find the problem. I have never had a 6 volt system and don't really won't to change it. I would prefer to keep it original since everything else is. Help me please.  

Answer
Since it runs with cable off battery, we know it is charging, but I bet if you do it with the lights on, the car will die.  You are either not returning enough electricity to the battery or the battery is bad. If you have no other problems (doesn't start if sitting for 5 days, etc) then I would guess the battery is good.

If you have a meter, check the actual votage output of the regulator, at the regulator. it shoud be above 7-8.5. Check it with headlights on also.

Make sure you don't have 12v headlights.