B7100-D Ignition Switch Wiring Question

On a B7100-D Ignition switch has anyone metered all the different connection terminals for all the different switch positions ?

I'm having issues starting and running now, and I trying to troubleshoot the issue. It is looking like the ignition switch is the issue. Would like to know what a good switch has for connectivity.

Would like to know what terminals are connected when...

TERMINALS:
30 - Always HOT - Wired to Battery via starter post.
AC
50
17
19

Thanks Wolfman. I do appreciate your help... Your explanation of the terminals is a big help.

I have been working her hard and the issues have been creeping up on me over a period of weeks. It started with the running lights fluctuating in intensity, then the headlights were not not working, then glow plug indicator not working, but I was still able to start her. Last issue was she would not start with pre-heat.

I was able to start her by turning key to start position for 10 seconds with clutch out then depress the clutch and start her. Now that no longer works.

I knew that terminal 19 was for pre-heat but was not sure about when 17 was powered. Your response cleared that up for me.

It appears that my ignition switch started breaking down and is now DOA.

As of today, I currently have no continuity between terminal 30 and 19 in the pre-heat position. No continuity between terminal 30 and 17 in the start position. No continuity between terminal 30 and AC in the run position. Terminal 30 to 50 are still working in the start position.

Today I was able to start her by using a jumper wire between 19 and 30 for 10 seconds then using the start position to turn her over.

Guess I am just trying to see what terminals have continuity to where, on a good switch for future reference and troubleshooting at this point.