I found a way to bring at full power the 950W astec aa23080 (initially, as described in the quote, it did not turn on)
You need to connect B6 with + 12V terminal, and A6 with C2. BP will start at full power. To turn on half the power, I can disconnect B6 from +12, the load will remain energized, and the built-in fan will turn off, then you can connect B6 with D2, then the fan will start spinning at half power. There is nothing to check the power of, but I think that since the fan was spinning at full power, the power of the unit was also full.