Hello Dadgumit,
we'll start with the basics....
the drum switch operates like this, as per the attached diagram.
Contact #'s - Operation
1-2)- normally open(N.O.) , Closes in AR and AV- Open in 0
3-4)- N.O. , Closes in AR and AV- Open in 0
5-6)- N.O. , Closes in AV - Open In 0 and AR
7-8)- N.O. , Closes in AR- Open in 0 and AV
9-10)- N.O. , Closes in AR- Open in 0 and AV
11-12 )-N.O. , Closes in AV- Open in 0 and AR
does this make any sense to you?