Pleasantly, it was a new problem, so I think the S relay fix worked.

This time it was the R relay. The way it’s supposed to work is that when the S relay is triggered, the R solenoid powers up, latching the R relay on until the machine is turned off again.

The solenoid was getting power, but it wasn’t quite strong enough to pull the plate in and trigger the switches. Looking more closely, I saw there was a rivet on the solenoid plate. It was not quite aligned with the vertical fin it was supposed to make contact with. I slightly adjusted the fin and it started working again.