Wiring schematic for 2166 Cub Cadet tractor - Fixya Jul 24, 2012SOURCE: Cub Cadet 2166 series. Mower will not engage. Unfortunately, the circuit is a little complicated - it involves the "PTO switch" (the switch you pull on to engage the mower), a "reverse switch" that senses if you've put the mower in reverse, and a relay operated by the reverse switch. I need a wiring diagram for a 2166 cub cadet lawn tractor Apr 29, 2012SOURCE: I need to find the wiring diagram for a Cub Cadet I tried to get wwwadet to look up your wiring diagram but without the serial number I could not get it done. You can go there and look up under parts.