When you shorted out the radio and removed it from the car now there is something that keeps killing your battery please don't say a short you know that much?
try and find any fuseable links in you wiring harness some times
when you ground out a wire it sends out a power surge that will
make a fuseable link to draw power even when your car is off. you
could even take the battery cables off you battery when the car is
running if it dies the charging problem is with your altanator or
relays. just a guess hope it helps RK