Small Engines (Lawn Mowers, etc.): JD S82 no spark, blade control, jumper cable

Question
Have not used this JD S82 mower in 5 yrs. Squirrels had chewed up the wiring.  Repaired wiring, cleaned rusty ignition switch terminals, and got engine running good.  However, it would die when trying to engage blade (not due to load).  Checked 4-prong switch in steering column.  It was broken, so replaced switch and throttle cable.  Adjusted position of switch re: blade control lever.  Due to switch being in pieces, I may not have re-connected the wires correctly to the 4 terminals.  However, starter turns engine fine, but now have no spark.  Color code may not be standard over years, but only purple/purple with allow starter to turn, leaving black/white connected to the other pair of terminals.  Both black & white appear to lead from same terminal on ignition switch.  However, only one purple lead is hot, then only when ignition switch is turned to "start".  I am confused.  Is wiring assignment to the new switch correct?  Is the ignition switch or plug connecting to the rear either defective or not making good contact?  Or am I missing something else?  (Since you may raise the possibility of other safety switch involvement, I should confess that issue became irrelevant years ago.)

Answer
If it dies when the blades are engaged it's a seat switch or a seized bearing on the deck.  It will take a day or 2 to dig out the S82 manual for some wiring assistance.

I can tell you this engine needs zero electricity to run.  Disconnect the white wire on the governor plate. This eliminates the tractors wiring harness.  Take a jumper cable from the battery + side and touch it directly to the bolt on the starter.  If it starts and mows fine you know it is in the tractor harness somewhere.  UIf still no spark you need a new coil.  The new coil will be electronic ignition so the points will no longer be a factor.

Sorry for the slow reply.  Best freinds daughter was electrocuted late last week.  S82s were pretty low on my priority list.