I discovered the short cable that connects the starter motor to the solenoid has disolved into dust. Unfortunately while the cable is connected to a stud on the solenoid it is not connected to the starter in a similar way. THere appears to be a small hole at the end of the starter casing were the wire passes into and must be connected inside the case of the starter. Rather than just replace a cable between two studs it looks like I am going to have to remove the starter to get at the starter end of the cable. Grrrrr. 