Cadet 2166 will not start

My neighbor has cub cadet 2166. The oil light is on but has good oil level. Starter will not turn over. Kohler engine

Check the condition of your battery. Use a hydrometer to check the specific gravity of each cell and write down the readings. Should see 1.280on a fully charged battery. Make sure all your battery connections are clean and shiny. Make sure the engine isn't stuck. Remove the sparkplug. See if the engine is free. Hal

As Hal said 1st check condition of battery & battery connections and weather eng can be rotated by hand.

The oil light being on when ign sw in on/run position is normal due to fact eng has a pressure sw on oil filter adapter & eng has an oil pump,light will go out after eng started if lube system working ok.Light has no effect on cranking system.

IF battery/battery connections prove not to be the problem & eng turns free,then take a jumper cable directly from battery pos(+)to battery terminal on starter,if starter spins eng then starter motor ok,check battery connections at starter motor & sol for starter that they are clean/tight,if connections ok then connect a voltmeter/12v test light to coil terminal on starter sol,when holding ign sw in start position check for voltage at coil terminal,if you get a voltage reading/light & starter doesn't crank eng replace sol,if no voltage at coil terminal work back thru wiring system from sol with a meter/test light & check brake sw,pto sw & ign sw operation.

Tell your neighbor to do a goggle search for cub cadet 2166+wiring diagram,there are several posted online for tractor wiring to help troubleshoot problem.

IF your neighbor doesn't have the electrical knowledge/skills and tools to troubleshoot problem,tell him to leave it for pros at local mower shop.