Ferrari 308 Speedometer Fail and the Fix

Ferrari 308 Speedometer Fail and the Fix. Back to wrenching on the 1980 Ferrari 308. The speedometer is a common problem with these cars. The instrument is electronic, connected to a speed sensor by wires. There are two versions of the speed sensor. The older version is turned mechanically by a rotating gear inserted in the gearbox, kind of like the MK2 Jetta and the TR3 I'm working on. The newer sensor has no moving parts and senses a spot on the flywheel as it passes the sensor. 1980 is the year of the new sensor, however my car is a very early 1980 and often has earlier version parts on it. I tried to fix the sensor that was on the car, but failed. Problem fixed after tracking down a source for the original style sensor and purchasing a new one.