What's making this noise?

[TxCowboy]

Have a 2016 Hill Country 26RB.

Have a faint whining/buzzing noise behind the circuit breaker panel. This would be to the right of the fridge and near the furnace.

I have everything turned except the radio (will figure that out later) and the propane detector. The outdoor fridge is unplugged.

The noise goes away when I unplug the shore power so it is definitely something powered by AC current.

Any idea what might be causing this sound?

[cowboy_71]

A fan used to keep circuits cool?

[cowboy_71]

Does it come on when you turn on lights?

[fhenn]

cooling fan to keep that area cool

[Russb]

Sounds like the converter cooling fan. It will come on as the 12v load increases.

[Dayle1]

If your frig is located in the slide out, then it is the cooling fan to help the frig since air flow is not as good when it is located in the slide out. Otherwise, it is probably the converter fan and speed/noise will vary depending on the amount of 12V power being consumed including the battery recharge circuit (so a very low or dead battery will cause the fan to run). The fan for the frig. MAY run anytime the frig. is turned on. The fan for the converter MAY run whenever shore power is available. So, based on your info, it is probably the converter fan. But if you have all 12V DC items turned off and the fan continues to run, then the battery is not up to full charge or defective.

[TxCowboy]

Originally Posted by cowboy_71

Does it come on when you turn on lights?

All of the light switches are turned off.

[TxCowboy]

Originally Posted by Dayle1

If your frig is located in the slide out, then it is the cooling fan to help the frig since air flow is not as good when it is located in the slide out. Otherwise, it is probably the converter fan and speed/noise will vary depending on the amount of 12V power being consumed including the battery recharge circuit (so a very low or dead battery will cause the fan to run). The fan for the frig. MAY run anytime the frig. is turned on. The fan for the converter MAY run whenever shore power is available. So, based on your info, it is probably the converter fan. But if you have all 12V DC items turned off and the fan continues to run, then the battery is not up to full charge or defective.

I'll go with this. I haven't pulled that lower vented panel yet but I did run on battery power for about 30 minutes earlier today so if the converter is behind there and has a fan, that is probably the source of the noise.

The RV is plugged into shore power and the appliances, lights, etc., are all turn off so I should be able to check in the morning and that cooling fan should be off (no noise).

Right?

[Dayle1]

Originally Posted by TxCowboy

I'll go with this. I haven't pulled that lower vented panel yet but I did run on battery power for about 30 minutes earlier today so if the converter is behind there and has a fan, that is probably the source of the noise.

The RV is plugged into shore power and the appliances, lights, etc., are all turn off so I should be able to check in the morning and that cooling fan should be off (no noise).

Right?

Yes, the converter should bring the battery up to full charge in maybe 1 hour depending on how depleted it was. But if the fan continues to run, there may be a problem with the battery like a shorted cell or low water level. To verify you can turn shore power off, then disconnect the battery, then turn shore power back on, should be no noise. If you have a battery disconnect switch, then that makes it even easier. There is also a very remote possibility that the converter itself is defective and trying to overcharge the battery or some other 12V high drain load that is accidentally on (but there really aren't any).

[Robb]

I'm guessing inverter cooling fan. Based on all of the reading I did when we purchased our ST33BD, Crossroads seems to use inverters that are marginal based on the current draw. If we turned on just two 12v lights while the shore power was plugged in, the fan never shut off. I just replaced all of the bulbs with LEDs and now it rarely runs.

[TxCowboy]

Originally Posted by Dayle1

Yes, the converter should bring the battery up to full charge in maybe 1 hour depending on how depleted it was. But if the fan continues to run, there may be a problem with the battery like a shorted cell or low water level. To verify you can turn shore power off, then disconnect the battery, then turn shore power back on, should be no noise. If you have a battery disconnect switch, then that makes it even easier. There is also a very remote possibility that the converter itself is defective and trying to overcharge the battery or some other 12V high drain load that is accidentally on (but there really aren't any).

I'll check this tomorrow morning and see what happens.

[TxCowboy]

Originally Posted by Robb

I'm guessing inverter cooling fan. Based on all of the reading I did when we purchased our ST33BD, Crossroads seems to use inverters that are marginal based on the current draw. If we turned on just two 12v lights while the shore power was plugged in, the fan never shut off. I just replaced all of the bulbs with LEDs and now it rarely runs.

This unit is supposed to have nothing but LEDs. I'll spot check a couple of lights tomorrow to confirm that.

[TxCowboy]

Checked on the fan noise this morning. It was off when I entered the RV and came on immediately when I turned on the interior lights. So it seems to be the converter fan. So thanks to Robb and others for your insights.

I spot checked a couple of lights. Seems most of the interior lights are LED. Not sure what type of light is over the dining table. Interesting bulb shape that I've not seen before.

The exterior lights seem to be incandescent. Not worried about the running lights but I would like to replace the porch and step lights with LED. The LEDs should be a little brighter than the incandescent lights that are currently installed and this unit doesn't have a scare light so a few more lumens would be good.

Thanks again for everybody's input.