Removing A/C evaporator - question???

You might want to test it before you reinstall. At room temp, you should be able to move the adjustment to close the switch, and may not be able to open it

After sitting in the 'fridge for a bit, the switch should open, and if cold enough, the adjustment won't close the switch.

As I said, that's a tube. It's pressurized with something, maybe even freon. If the tube corrodes or gets kinked, etc, and leaks, it's NFG