Variable Speed Sensor_______________________________

The speedometer is driven by the variable speed sensor (VSS), which is currently available only from OPMD (


One way is to use a speedo with a drill and 12 volts.

It looks like it won't be easily repaired, except for something like a broken wire.

Above, there are two different styles of sensors shown (thanks to Jeff Herson at Merkur Parts Midwest for the donor). The plug that fits into the body holds a circuit board with (probably) a transistor that pulses when the vanes of the rotor pass between it and a magnet held in the body of the sensor. Transistor shown at about 10 o'clock on the circuit board.

The transistor is shown at about 9 o'clock on the circuit board. The magnet is visible at about 6 o'clock behind the vanes in the body.

As much as I had to cut this one to open it, it would still probably be usable, if it were repairable. That I leave to the electronics experts. See next picture:

This is the top of the circuit board, with several other components.