FWIW jumping back to the engine for a post, my Clamshell toasted a battery in a season as I didn't realise it was a "rectifier only" until I got my plotter & my jaw broke the console whenI asked it to display batt voltage! (17V @1500rpm!
) It also instantly explained why I was eating through nav lights bulbs.......
I got a combined rect / reg off a gubbed Suz O/B and strapped it to the side of my air box (to keep it cool - beware the regulators generate heat). Yes, I had to cut & crimp new connectors on, but it works a treat, & provides a nice constant 14.4V when the engine is on.
Also not chaged a nav. bulb since!