Jack,
We may know one another! I too started out as a 52B20.
I have to run, but, if you have 24 volts on S1-2 & S1-4, you have to have voltage on S1-6 & S1-8, unless the S1 jumpers are missing. The first two versions of S1 had the jumpers external, the third version had them built in. So test again, in the run position. If still no joy, then the jumpers are missing. I have to go now to work. Later,
Guy wiltfang