Quoted from MarkG:I agree that activating the relay (by manually pushing in the armature that moves the switches the way the relay would) would be a quick and effective check if you're comfortable working on game with the power on. If you're not comfortable with that yet then the meter is an alternative.
All coils are wired in on one side to the transformer. That's the black wire. The other wire on each coil goes thru a series of switches to get to ground and complete the circuit. These are detailed in the schematic. A meter is not going to tell you much.