alternator tech help

I could type out the tale of "foglamp fryed fords" and how their engineers fecked up as a good example but instead I'll keep it short and simple...
Keep those large gauge wires carrying high amps out of the cabin of your car.
Use relays with wiring and terminals rated for 30 amps. Place maxifuses in those circuits.
You can use the factory wiring, fuses, and switches to signal those relays.