the big three

i dont fully understand one part of the big three.  ive got a 91 toyota pickup, with a 120 amp alternator i just bought. the ground wire from the battery to the frame is 4 gauge. im not 100% sure what the next one is, but i think its a wire from the engine to the frame, in which case if it is its 4 gauge as well. the part that i dont understand is the wire coming from the alternator. on my yota there is a single wire with a ring terminal, and a plug with a few different wires. im guessing the single wire is the one i beef up, but what do i do with it from there? do i run a fuse inline and run it straight to the battery? what do i do with the old single wire that i took off? 

bump. anyone know?

The way i would do it is leave factory wires there, Then add a 4ga wire from your alt to the battery, with an inline fuse in it... Then run an additonal ground from your negative battery terminal to your frame. And also a new ground from your block of your engine to the frame is the 3rd wire... All that is the big 3, and you should notice a difference with those upgrades, because you can move more power thru 4ga than stock 10ga wiring

i did similar on my yota. ran a new 2 or 4 gauge from the battery to the starter. and the same size to the frame on the negative. then bounced over to the block itself, not the motor mount. and added one from the battery to the motor itself. it started alot easier after that. i havent done any alt upgrades yet. good idea though. i just got a deck and 6-1/2s. no power anything. and decent headlights. lol.