Check out the circuit to see what is going on.....do you have the switch module?
Put your 12VDC across the red and brown wires on the 4 wire power connector. When you have it powered, you will probably have 12VDC on pin 2 of the 5 wire connector. This powers the switch contacts. I would guess that the variable resistor is limiting the motor torque so when it closes, the motor doesnt overpower the linkage. Keeping it powered up, try a switch; if it doesnt work, try the other switch. If you dont have the switch panel, jumper pins 5 and 2....does it move? If not, jumper pins 4 and 2. If you dont have the switch panel, DONT close the roof all the way because the motor may have full torque......just tap the jumper wires together to see if it tries to move.