have a 1990 5.7l tpi swapped into my truck.

Heres what i know:
engine runs, starts, charges
there is a either a short or incorrect wire setup within the Heater and ACC circuit
- heater circuit: drains the batt when truck is off when fuse is plugged in
- acc circuit: alt will not charge when fuse is plugged in
i removed both fuses , no drainage issues


Problem:
I don't know where to start, this was someone else's work.
i dont know if the Mass air flow, MAP, or Iac are working.
obviously the acc circuit is a problem for some of the engine components.


how can start "fixing"/ organize the wiring and making sure these sensors are working?



side note:
lately combustion seems to be failing while full throttle.
i can back out of the garage and drive slowly but I have open the throttle wide the rest of the ride will be choppy
not sure if this has anything to do with the wiring. (im pretty sure it didnt do this before i removed the fuses.)