im gettin just about done doing an engine swap...85 firebird...2.8 to 305 carbed( was a tbi motor out of a 89 trans am but i switched the intake)

a little wiring is all thats left

on my alternator i have 3 wires coming out of the plug
a heavier red wire i hooked up to power with key on correct?
a black wire i hooked up to the gauge correct?
and a white wire i cant figure out??

then i gotta wire my cooling fan...dont know how to hook this up

also the three relays that are sitting by the brake booster do i still need those?
there was a red heavier wire running on the passenger side right below the windshield wipers....whats that for?

and finally can i just leave my ecm in and it run my fuel pump?