If the Interior Lights ( 12 volt auto ) in your Living Quarters are pulsating from dim to bright, the most likely cause, is the Charging Unit in the Converter is going out. The Charging Unit is like a Battery Charger that converts 110 volt to 12 volt which in turn charges your batteries and makes all the 12 volt appliances and lights operate in the Living Quarters. It is possible you will notice this problem more with the Generator running as opposed to just being plugged in to 110 volt with the Power Cord. (See also Microwave Troubleshooting)