radio issue
 

So thougjt i by passed the battery issue but i didnt. So i had a old radio and everytime i turned it out shortly after my battery died. So what i did was wire it through the a/c instead of were it was originally strait to to the battery. Idk if its a alternator or if the ground is bad but after i hooked it up through the a/c i left my truck alone for a hour or so and its back to step 1 i am lost please help!!