An auction is being planned to sell off all of the equipment and machinery left in the former Janesville General Motors plant. Professional Industrial Appraisal will be conducting the four-day on-line auction slated to start next Monday. Some of the featured equipment includes robots, electrical controls, pumps, motors, tanks, and shop gear. Originally built in 1919, the Janesville plant was the oldest in North America until it ceased all production almost a decade ago.