Hi... this is my fisrt time in here..I do not know if I am doing it right..anyways I have a 94 LS 400 that it has voltage drop-drain,, and I have discovered that disconnecting that fuse where it says AM1 the short goes away,, any idea what is this fuse for???apreciate it

I think the AM1 fuse powers the ignition circuit and is a whopper, 40A minimum, it does alot of other things too so you just found the "head" of a large tree of connections. Further tracking is required.