DETROIT – The company that makes heavy-duty diesel Ram trucks is telling some owners to park them outdoors due to the risk of an engine fire. Fiat Chrysler, now part of Stellantis, is recalling just over 20,000 of the trucks mainly in the U.S. and Canada. The company says the 2021 pickup and chassis cab trucks have heater electrical relays that can short, overheat and in rare cases cause fires. None involved customer vehicles. The recalled trucks are equipped with 6.7-liter Cummins diesel engines.