Common float type low oil level switch used on many Generac and Briggs and Stratton engines, especially those used on generators and pressure washers. This switch grounds the primary winding of the ignition coil directly to the block when oil is low and does not use any intermediate relay or sensor.
This switch is easy to disassemble and clean. Use a screwdriver to pry apart the cover from the body. If the switch shows continuity when there is sufficient oil in the crankcase, the float probably has stuck to the body due to old, thick oil, wrong viscosity or low temperature. If the switch shows no continuity when the oil is low, take it apart and clean all contact parts.
A small magnet in the body of the switch holds the switch closed below a certain oil level, reducing intermittent on /off conditions.
The circuit path is from the nutted terminal (A) through the body (B) to the stamped sheet metal contact (C) to the spring wire (D) to ground in the mounting hole.
Left: Angle of operation should not exceed 30 degrees.
Center: The lamp at 'G' is optional.