Couldn't really tell anything about the isolator be testing it. But I did find it and it is a Guest 2430 (took a lot of disconnecting stuff to find this).
I never found that soleniod switch and don't believe it is in the system.
The alternator feeds the isolator. On the same lug as the alternator is line to the inverter
switch (just like a 1, 2 both, off switch) and on another lug is a line to the start battery.
Now when I got to the boat the inverter switch was off. The start battery was reading 13.2 V because it was being charged by the trickle solar
panel, the house battery was reading 12.8V (beczause I motored 4 hours to get in the other day and everything has been off since then).
I turned on the stereo and 20 minutes later the house battery reads 12.2V. This is my "good" battery and it believe has lost
the war (got new batteries for both house banks on the way home). The "bad" battery is less than 11V but is competely disconnected.
I turned the inverter switch to 1 (the only house battery) and the start battery voltage drops to 12.2V. I turn it back off and the start battery slowly goes back up to 13.2V.
So near as I can tell that inverter switch is connecting the house and start batteries. And the only way to do that is though the isolator.
Since the start battery powers the windlass
; I'm thinking it is much less trouble to replace the isolator that to redo the power to the windlass
in order to use some echo type charger.
Thoughts are welcome!