1. The Lock/Unlock voice will activate in both extend and retract modes
2. Are you plugged into Shore Power? If not, turn on the genset to get the Power Converter to help power the system.
3. On Newmar, when a motor stalls, the BEST way to test for either a Bad Motor or the Control is to disconnect the 2 wires to the motor at the motor and attempt to retract with a good 12 volt battery source direct to the 2 motor wires. IF the room retracts, then the odds are the Control is bad. If it does NOT, then the motor is bad. IF the motor is bad, the only way to retract a Newmar slide is to loosen BOTH "Trans-Torque" Bushing nuts at least 4 turns. That releases the motor from the driveshaft and then you can use a pipe wrench to manually turn the driveshaft to retract the room. When I state 4 turns that is because when you attempt to release those nuts they will break loose about 3/4 turn and some think that releases them. It does not. You then break it loose a 2nd time and turn at least 3 more turns.
4. I assume you have the Level floor slide out. That points to a bad motor as the short 8 inch slide UP the ramp is what causes a bad motor to stall. You could also have 3 or 4 people on the outside PUSHING the room in while attempting to retract instead of releasing the Trans Torque nuts. With that extra help you may get the room up the ramp and once on the level floor the motor may continue to bring it in. If you can do this and it works, then replace the motor.
5. Also, look at the Motor and Transmission case. See if you see any green oil on the case or dripping off the case. If so, then you have to replace the motor. Newmar sells the complete motor/trans as a unit. Doug