deck cuter switch is shutting down the rider why

[drd1763]

My JD was running OK but now the switch that turns the cutting blades on shuts the lawn mower down looking for help please .
Also does anyone know does a belt run from the deck to the lawnmower itself or not .as it looks Luke I'm missing one .but not sure as I bought it used and only had it for two days .

 

[ILENGINE]

What model of JD do you have. It can make a difference in what wiring diagram your mower uses to determine causes.