msna,
If you are talking about the top and bottom spades on the side of the switch closest to the center of the machine (they have red and gray wires connected to them), then the switch is working properly. If the other spade that has black wires connected to it is part of this test, then the switch is not closing.

you must have a short somewhere between the yellow and the purple/blue lines in the diagram below. That's why the light is on even when the safety thermostat is off. If you checked the switches. Look at the thermostat spade tabs and see if they are touching the boiler body. The boiler body could cause a short if the tabs where pushed down.

All of the thermostat spades are clear of the boiler body. I have replaced all three of the thermostats trying to fix this issue.
Could the problem be that the yellow heating element supply lead is shorting to the boiler where it goes thru the lid?

You've proven the element is shorted to boiler ground through the boiler water.
Replace the element.

Thank You very much