I need to find out how far back I have to go to correct a mistake I obviously made. I have a save at the Planetary Room, which I've gone back to twice and gone from there. I've opened the gate to Chamber III, traveled through the wine cellar and got to the Refinery, gone into the Mine Shaft, walked over to the mining cart controls (here is where I have the problem) pulled the clutch to switch the track, but the track doesn't switch. The WT further instructs to throw the right switch to the up position and the left switch to the down position, but the left switch pops back up to the up position every time.

Is the mine cart free to travel the tracks???