So, I turned off the shore power breaker at the pedestal but I didn't disconnect shore power.
I connected the boat ground to the unit before connecting the shore ground to the unit.
Shore power is 110V.
Diode test on the multimeter shows high voltage indicating open circuit.
I don't think so. Mine shows open circuit or very high resistance.
Some galvanic isolators have 2 diodes in series to give 1.4V drop, a basic DMM may not inject a high enough voltage to make the diodes pass a current.
I have seen a test method with a 9V PP3 battery and a small 12V light bulb (not an LED). Connect the battery positive to the light bulb, then to one side of the galvanic isolator and the other side of the isolator to the battery negative. The bulb should glow dimly, then check the other direction by reversing the leads on the isolator.
