EXPANSION TANK CAP; Fiesta. A cover that prevents foreign debris from entering the container. Cap for the Hybrid Inverter Coolant Reservoir. Engine Cooling. From 07/03/2013. From 10/01/2014. From 12/23/2014. Location-Reservoir. Radiator Cap. To 07/03/2013. To 10/01/2014. To 12/23/2014. Assembly -. Drive Motor Inverter. Engine.