Originally Posted by rfkneller
Thanks for the replies. The shore power cord was brand new.
After reading other threads I think I was mistaken about the reverse polarity indicator. I think I was throwing the test switch and it was indicating that the alarm
was in working order.
The problem could be the very old GFCI outlet at the electrical
panel. I have seen them become non working with age and that one could be about 30 years old.
If it is not that, then it will probably be the wiring in the boat which has been modified and added to by previous owners.
Correct. Some shore power systems were equipped with a "Test" Switch that enabled one to test the "Reverse Polarity" Indicator light.
For all shore power system equipped with reverse polarity detection:
1. Shut off the marina power post AC breaker that you intend to use.
2. Shut off the vessel main AC breaker.
3. Connect the shore power cord to both power post and vessel.
4. Turn the power post breaker on.
5. With the vessel main AC breaker off, check the reverse polarity light. (It should be off, if RED you have an issue.
6. If equipped, flip the reverse polarity test switch. If the Reverse polarity indicator does not come on, you can't trust the detector, get it fixed before flipping the main AC breaker on.
7. If the reverse polarity indicator is off, when connected to shore power, and on when the test switch is depressed, all is well, turn the vessel main AC breaker on.