As you can see from the picture below, I have three pumps. The first is enabled if heavy oil > 0. The second and third are for light oil and petroleum. All three are connected to a circuit which is also connected to the train stop. I know from the power poles that the circuit is reading correctly (the train parked has 75k light oil), and in the picture the light oil pump's circuit is enabled.
But nothing happens! The pump isn't working. It's connected to power. The train is at the station (running on automatic).
I must be missing something, but what?