Battery Draining Problem

Disconect the battery and put it on a charger, when it's charged use a volt meter to take a reading across the terminals which should read over 12 volts. Then hook up it up to your car again and take another reading. If the volts starts to drop below 12 volts something like a light, stereo or alarm could be drawing from the battery.    

I had a similar problem with my 72. I didn't have a volt meter so I took a spare tail light lamp, attached a wire to the brass case and one to the center solder connection. Unhook the negative battery cable, hook 1 wire to the cable and the other to the battery post. If there is a short anywhere in the car, the lamp will light. Then, one by one, remove the fuses from the fuse panel until, hopefully, the lamp goes out. that should put you in the ball park about just which circuit is shorting. Then, start chasing the wires for that circuit and look for a short to frame ground.