Add the turkey breast, sliced lemons and limes, and orange juice mixture in a large ziplock bag or bowl. Put it in the refrigerator and let the turkey breast marinate for 12-48 hours.
Once the turkey breast has marinated, place it in the crockpot along with about 1/3 cup of the marinade. Add the onions and carrots around the sides of the turkey.
Once cooked through, you can transfer the cooked turkey breast to a 9 x 13" roasting pan and broil the top of the turkey breast for about 2 minutes, or until lightly golden brown.