lost in an abyss of focus frustrations

hey guys i need some serious help.....i bought a used ford focus from 01 nice car but i've taken it to the shop like 5 times since i got it....i seem to have a problem going from the battery to the cd player..cuz everytime there is a cd player connected or radio it drains the battery, when i un plug the cd player the car is fine but as soon as i hook one up the battery drains over night.... can anyone help me... i'm lost in an abyss of frustrations!

There are 2 power leads to most radios or CD players.
The main one is supposed to go on and off with the key like the rest of the accessories.
The other is only for backup memory of your favorite stations, etc., and is powered all the time.
It seems to me you have the always hot wire attached to the main input, so the CD or radio is on all the time and would then drain the battery.
Recheck the leads.
Sometimes even when they are in a harness, they are mixed up.