What is the voltage at the TM plug? You may have corrosion where the wires attach to the plug.
How do you know the batteries are good? Age, voltage after setting or just a good guess? Not being a SA but batteries can be bad even if new.
I haven't checked the voltage at the TM plug, I'm not 100% sure how to do that. I'll check to see if there is corrosion where the wires attach to the plug tonight.
The batteries are 2 years old this month and have sat for a few months with voltage still over 12.5V before I started taking the boat out a couple months ago. I guess I could take them out to get tested to be sure they are still good.