If I turn on only one light in my 5th wheel, I get a hi-pitch squeal. When I turn on a second or more lights, the squeal stops. Is my inverter doing this? A problem?
CAn the squeal happen with any one light or just a certain light? Have you recently upgraded to LED's? Can you put a regular old incandescent in one light? Testing would be turn on light with LED. A) Squeal B) NO squeal IF A) replace led with incandescent and repeat test. Could be a bad or crappy led lights