Understanding Josh Malks Shift Schematic

JIM.OBRIEN wrote: Hi AJ, Give me a call or email me and I will walk you thru the troubleshooting. I'm in the club directory.

Start by putting the switch in first or reverse and see if there is power at the #8 wire on the solenoid.
Jim

Thanks. My dad and I will be back on it tomorrow, so I'll try you then.

Hi AJ, Give me a call or email me and I will walk you thru the troubleshooting. I'm in the club directory.

Start by putting the switch in first or reverse and see if there is power at the #8 wire on the solenoid.
Jim

Attached is a copy of Josh's redrawn shift schematic (originally drawn by Reg C. Taverner, in the 50s). This is super helpful but I have a rather dumb question. Our issue is the interlock switch moving the horizontal shaft to either the L or R position. If I manually put the transmission in either R, or 1st/4th it will move to the middle for 2nd/3rd. I suspect the issue is in the selector switch, but would like to methodically work my way back. Could someone explain using a test light how I can use the box in the lower left corner of the diagram to diagnose the interlock switch? I feel stupid, but I'm not sure I understand what "connection between switch points" means has far as voltage at the contact.
Thanks! A.J.