Isolators and alternators and relays, oh my!

Still haven’t got the isolator working…I can’t help thinking how simple it would be to do it with a continuous duty normally off relay, triggered by the blue wire from the alternator which activates the relay for the “charge” idiot light.

A fairly small gauge wire (with a fuse) to charge the 2nd battery should prevent any sudden, drastic transfers. So simple and cheap…I think I’ll try to return the isolator…