Ammeter, Large Diameter, illuminated. This is an optional version of Part# 5016ES. It has a LED lit Ford script face. This ammeter is built exactly from Ford’s original drawings and does not need the adapter ring that is needed to make the small 1926-1927 style ammeters fit in early ignition switch plates. It has steady readings even on rough roads, 20-0-20 scale and a Ford script. This ammeter will not fit in a 1926-27 ignition panel and is not recommended for use with an alternator.