New Alternator.

[AKLJ8]

I have dual batteries in my Scrambler and use a different kind of system. Rather then an isolator I have a continuous duty use Solenoid wired between them. It is wired to a switch on the dash and a oil pressure switch on the engine. It connects the battery when there is oil pressure for charging and disconnects it automatically when there is no oil pressure. If I leave the lights on it is isolated and I use the dash switch to connect it to the main battery and start the jeep. It was about $30 bucks at Napa for the parts and has worked great.