fuse box/starter wiring

[Strugglebucket]

well i want the battery in the trunk now. so i'm running a single wire from the alternator to the battery. that leaves me with the wire from the fuse box (the one in the engine bay) and the wire from the starter needing a home.
my question is can i splice those two together? or will that cause the main fuse to blow when the starter clicks on? i know the engine bay fuse box has one power wire input from the alternator and another from the battery but i'm not sure exactly as to why it needs both.
sorry if this is confusing.

[AZmike]

The positive on the battery needs to reach the starter and fuse box. Everything else can be taken care of with the factory wiring.

[Strugglebucket]

i know i COULD just run power from the battery to the fuse box and starter and everything would work.
the thing is, i now have a 120 amp alternator and i want to run 1/O power wire directly from the alt output post to the battery (and to the stereo, he he), thereby bypassing all that factory 4awg alt-to-fusebox-to-battery crap.
i will still have the factory wire hooked to the alternator, of course.

i guess my real question is: is the fuse box +batt connection in any way isolated or fused from the fuse box +alt connection? or is it a parallel buss and they're just connected on opposite sides?

[SteveDX89]

The connection is not fused unless you put a fuse in it.

[Mac]

Fuse #21 (70 A) is between the Batt + and the alternator.

[Strugglebucket]

thanks! that makes sense.