I have a promariner galvinic isolator on the 353 the monitor keeps flashing fail on the ground wire that's when I use the shore power cord. If I plug the pig tail and an extension cord it is fine. I have tried three different shore power cords at marina all are giving same fail on ground wire.
Anyone run into an issue like this or have an idea anything in particular to check for?
I am ready to eliminate this system
I checked voltage at power box and also at end of the cord with a volt meter I am getting 119.2 volts
Thanks
Boat is an 04

I'm not sure, but if it is reading fail, isn't it the shore power source? See if you can try another boat at the marina using the same outlet. Just a thought.

Dave