No, consent is not necessary, since a conservator is appointed by the court; since the conservator is appointed by court order--and is often appointed for mentally incompetent persons--the conservatee's consent is not a requirement. That doesn't mean, however, that a court may not take the conservatee's feelings into account; e.g. if the conservatee has a strong dislike for or a problematic past with a proposed conservator, the court may decline to appoint that person.