For lime sauce, juice two of the limes into a bowl (cut remaining lime into wedges for serving). Stir mayonnaise and chili powder into juice. Transfer 1/3 cup of the sauce to another bowl; toss fish in it. Set aside remaining sauce.
In a large skillet heat oil over medium heat. In a shallow dish combine flour and salt. Working with about a third of the fish at a time, toss fish in flour mixture and add to hot oil. Cook for 2 to 4 minutes or until fish flakes, turning to brown evenly and adding additional oil as needed. Drain fish on paper towels.
Wrap tortillas in paper towels; heat in microwave for 30 seconds. Top tortillas with fish, cabbage, carrots, and jalapeno. Drizzle with Lime Sauce and serve with lime wedges.