Is the wire gauge smaller from battery to fuse box and larger air coditioner?
Yes, the wire gauge is typically smaller from the battery to the fuse box and larger from the fuse box to the air conditioner. This is because the current draw of the air conditioner is much higher than that of the fuse box. The smaller gauge wire from the battery to the fuse box is sufficient to carry the lower current draw of the fuse box, while the larger gauge wire from the fuse box to the air conditioner is necessary to carry the higher current draw of the air conditioner.