[Richard]

I am probably dead wrong.

I can't help but think, when you hear hoof beats thinks horses. No cooling and low amperage on a compressor would be classic low or no gas in the system.

But, you have confirmed numerous times, that the low amperage follows the wiring on the board, not the wiring to the compressors.
So my idea doesn't make sense.

The second situation where the fans started working on low is also puzzling.

That neutral wired liked that, is very interesting. And different than the SCS units I have had my hands on. I might take the time to unfurl all that wiring tomorrow when switching boards and truly understand what goes where.

You really cooked up a good one here !