Have DUI dist am not using a ballast resistor when running at idle I have 12.35 volts at dist. Have engine to frame ground,cab to frame ground, separate grounf from dist to cab at about 200 deg it starts running rough then quits, next morning it will start up. running a alternator with enternal reg when runiing have 12.35 volts output and the same going to battery. Have put 6 new mods in dist from cheap to acell.