do not replace anything yet ! first check the electrical system . disconnect the negative cable ,3 o' L' S1 L* R1 u {+ f
connect a test light between cable and battery post . if the test light lights up bright , there could be a short circuit somewhere . pull out each fuse to see until the test light goes dim , 5 @, q' ?4 N: p5 `/ S: V5 I; P, s# `now you know in which that device is draining the battery .