§ 605. Advisory and planning boards. The county executive, upon authorization by the board of supervisors, may appoint a board of electors of the county to act in an advisory capacity to himself or to the head of any administrative unit under his jurisdiction. The members of the advisory board shall serve without compensation but shall be allowed and paid actual and necessary expenses incurred by them in the performance of their duties. It shall be the duty of members of any such advisory and planning board to consult and advise upon county problems but not to direct the conduct or administration of county affairs.