no headlights or anything+upgrade alt question

Ok- going to run a 6 gauge wire from alt to battery post on relay with a 10 gauge fusible link. Is this still going to get electric to the dash and headlights? Can you tell Im no electronics whiz? lol. Seems to me that since im bypassing the ammeter gauge, I still wont get power to the dash-right? Is there another wire im missing somewhere that gets power to inside the car and the head/tail lights? I always thought thaT THE lights were basically a straight shot from battery to switch to headlights?? I dont even have my 4-way emergency flashers working??!!