Brush peppers, squash, and onion with half of the oil. Grill vegetables in a grill basket or on a greased grilling tray on an uncovered grill directly over medium-hot coals for 5 to 8 minutes or until crisp-tender, turning occasionally. Remove vegetables as they are done; set aside and keep warm.
Spread one side of a tortilla with some of the ranch dressing. Top with some of the cheese. Spoon about 3/4 cup of the grilled vegetables atop cheese just below center of the wrap. Top vegetables with some snipped cilantro.
Fold bottom of tortilla partially over the vegetables. Roll into a cone. Repeat with remaining ingredients. Lightly brush outside of wraps with remaining oil.
Grill filled wraps on the rack of an uncovered grill directly over medium-hot coals for 1 to 2 minutes or until tortillas are lightly toasted and cheese begins to melt, turning once. Makes 6 wraps.