United Auto Workers members at the Chrysler assembly plant in Fenton, Mo., were scheduled to return to work today after voting to end a two-week-old strike. UAW members ratified a new local contract by a 70% majority. The plant is one of two that builds Chrysler’s popular mini-van. A spokeswoman said the walkout cost Chrysler $3 million a day. The strike began Oct. 5 when 3,200 union members walked off their jobs after negotiators failed to meet a contract deadline.