After cleaning furnace, went on second trip this past weekend and furnace did work but camper lights were constantly dimming when blower on furnace came on, and also when furnace shut off I could hear humming from converter and lights would dim for a little bit and then would go to normal, I think the problem is the converter because when plugged into my house im giving converter a true 30 amp connection, this problem only happens at campground so I think there is sub par 30 amp connection, any suggestions would be great.