[topjustice]

After winterizing my 3791RD and moving it inside my garage for the winter I removed the batteries, unplugged the inverter, and plugged it in using the power cord. I noticed that the converter now has a steady hissing sound. It’s been about three weeks now and still doing it. Everything inside works fine, in fact if I turn on one of the light switches in the control panel the hissing stops. Turned off it starts hissing again. Since it’s inside a secure garage I like to keep it plugged in so the electric clocks, the satellite tuner box, etc. stay on. Has anyone had this hissing sound after removing the batteries while plugged in?