in the batt management system compartment under the hood, I tested the auxiliary start solenoid (going to the house batts) for 12v DC while sitting and unplugged and found it was 12.88v (like reads at the batteries also) and while idling and was -1v. also, the other side of the solenoid going to starting batt and found was also 12.88v at sitting and unplugged but went to .26v while idling. saw a demo that recommended starting there. that also explains why the voltage doesn't change at the converter (leads feeding power to converer) with the main breaker off vs. on