Unlikely that a new actuator is defective, but anything is possible. If the previous actuator was working with the distribution wiring and the ASC1 and nothing else has changed, I would focus on the new actuator. Did you first test the new actuator inside at the controller?
Is the actuator already mounted on the dish? If so, probably easiest to first test the actuator without the power/ sensor wires and ASC1. Disconnect the wires at the actuator and use a 12volt battery to power the motor. Check the reed switch with an ohm meter to observe the contacts open/close cycling as the motor moves. If the switch is cycling, then check the sensor wires for continuity by twisting the S1/S2 wires together and use the ohm meter to check for open or closed circuit. If the meter indicates a closed (short) circuit, its time to move indoors to continue to check the wiring. If it is easy to bring the ASC1 out to the dish, you might try connecting the M1/M2 and S1/S2 with short jumpers to test operation without the distribution wiring.
If everything tests ok to this point, connect the M1/M2 and S1/S2 distribution wires to the actuator. Now go indoors and connect the 12v battery to the M1/M2 wires. While the dish is moving, use the ohm meter to check the S1/S2 wires for switch open/close cycles. If the motor is moving and the meter indicates open/close cycles, connect the M1/M2 and S1/S2 wires to the ASC1 and test movement.