OK A lot of technical crap to say "bad limiter" at minimum. The limiter is a set of mechanical points. If those points were closed as they should be the resistance from I to A would be zero. Its supposed to be zero.
To continue...
A to S and I to S would be the same 20
I to housing should be 50.
A to housing would be 50 also.
S to housing would back feed to show 70 or the total of both windings 50+20
A .X to X.X ohm variance from these readings could come from you meter leads.
So your 20.7 is really 20. I'll guess your meter leads together show .7
If I wasn't retired I would suggest you ship all 3 thermal gauges to me.
You did get me to open the book so that's something. LOL Good luck with them.
