Stx38 turns over but won't start

I have a John Deere Stx38 (160001 - 210000) that will not start. It was running fine and got bogged down with grass and stalled. It now will not start. It turns over and there is spark at the plug. I have done the troubleshooting steps and all the wiring seems fine and safety switches are working. When doing the cranking circuit test (from technical manual) I do not get battery voltage at S2 when in the run position I get just under 6 volts. I get the same voltage on the purple wire of the starter solenoid. I get battery voltage at S1. The manual says to replace the key switch. I just want a verification before replacing the switch. I would have expected a bad switch to have 0 volts.

Thanks in advance.