[Mike Andrew]

Thanks all for the input. I will replace the battery first and proceed from there with my meter looking for 13.6 VDC on one of the lights. Always thought that the converter bypassed the battery so battery condition was not an issue and that is why it has not been replaced.
Now that it has been mentioned, I have not heard the fan running my last few trips up so that could be at the root of my problems and it is replacement time.
Looking online, I have found some "direct replacement" units for the NLA Parallax 7345 which are more modern units. Rather spend now than buy a used Parallax and do this again.
I am done up there until Spring so I have plenty of research time over the coming months.