I`d also recommend disconnecting the negative lead from the battery and hooking up a meter in series to measure amperage drain. Or milliamps. DON'T turn the key on, just do it with the key off. That will tell you if you have a component or wire going to ground. If you do have a short, pull and replace 1 fuse at a time until the meter drops to zero. That will tell you which system to start looking at.