Troubleshooting humming sound from inverter/charger
I replaced the 4 house batteries a couple of weeks ago and have been on shore power since then. I unplugged from shore power and started up the MH and let it run for about 30 min or so. When I turned the engine off and plugged back into shore power there is a constant humming sound that can be heard inside the MH coming from the inverter/charger.
I have checked the voltage on the 4 house batteries and the volts are good.
I have on/off buttons for the inverter and for the charger on the inverter/charger and a remote on/off button for the inverter inside the MH. I've turned the inverter off, charger off and the humming sound is still there. I've never heard this sound since I've owned the coach.
Has anyone experienced this?
2001 Fleetwood Discovery 37'
330 CAT HP, Freightliner XC