Classic/Antique Car Repair: Battery Power Draining, altanator, ford mustang

Question
I have a 64 Ford Mustang. The battery drains After about three days use. I thought it was a dfective battery so i bought a new one. It drained quickly. Then i changed the ground that was connected from teh negative to the engine to teh negative to the body. It still drains. Also, when i turn on the car the ALT light turns on. What could be draining my battery?

Answer
HECTOR;
a 64  ford mustang  it could be worth a good buck.well it sounds as if your altanator is bad or the fan belt might be loose. I would put a volt meter on it and see what voltage you are putting out to the battery it must be at least 13+ or so.as that will kill the battery and soon enough your new battery will be no longer any good. so get it looked at asap.  ok ....>>><><