Fill a large pot with lightly salted water, bring to a boil, and stir in the macaroni. Return to a boil and cook the pasta uncovered, stirring occasionally, until cooked through but still firm to the bite, about 8 minutes. Drain well. Whisk together the soup, milk, and onion flakes in a large saucepan over medium-low heat. Bring to a simmer, and stir in the sausage links, cheese, and carrots. Bring the mixture back to a boil, stirring frequently, until the cheese has melted and the mixture is bubbling. Stir in the hot cooked macaroni, and serve.