System: engine cooling system; fan.vehicle description: motorhome chassis built with 6.5L diesel engines and 7.4L gasoline engines.note: owners who take their vehicles to an authorized dealer on an agreed upon service date and do not receive the free remedy within a reasonable time, should contact chevrolet truck at 1-800-222-1020 or GMC at 1-800-462-8782.also contact the national highway traffic safety administration's auto safety hotline at 1-800-424-9393.