Ah! Good practical reason!Both azimuth and elevation must be correct. It is easier adjusting dish elevation when the motor is closest to its zero reference. Especially if it's a heavy 1.2m dish.
And to add: the 4 degrees arc difference would be 7 degrees azimuth difference, for location about 33.9N, 118.2W.I was thinking....since the receiver thinks it's on AMC21 but the dish is actually on Echostar 9 off by 4 degrees can't I just rotate the whole assembly until I get to AMC21 ?
Final check point in cases like these: As you did reset the motor at zero degrees, the motor should go exactly there with the GotoReference/GotoZero command from the receiver. Does it do exactly that?