Odd noise from Battery Compartment? Solar recharging?

[02interstate]

All,

We took a trip to Tucson this weekend and after arriving (440 miles) and turning of our '12 interstate we noticed an odd noise coming from the right rear of the van. It was a soft "ruurrr, ruurr" type noise. I know that is an awful description. - sorry.
Any ideas what this could be? Batteries? Solar panel charging batteries?

The van is new to us and this is our first big trip so the sound was a bit scary. I ended up turning off the "big red" switch under the sofa in the back that shuts off all the power and the sound went away.

Were back home in San Diego now and as of this morning the sound is not their (it has been overcast here so vs the 90 degrees in tucson so I am leaning toward thinking that this might be the solar panel charging the batteries?)

Thanks for any help - and excuse my ignorance if I missed a thread on this.

Thanks

[Protagonist]

Originally Posted by 02interstate

We took a trip to Tucson this weekend and after arriving (440 miles) and turning of our '12 interstate we noticed an odd noise coming from the right rear of the van. It was a soft "ruurrr, ruurr" type noise. I know that is an awful description. - sorry.
Any ideas what this could be? Batteries? Solar panel charging batteries?

Solar panel is silent, and the solar charge controller is not located where the sound was coming from anyway.

What you might have been hearing is the cooling fan for the inverter/charger.

It's also possible, if you were running the water heater on propane, that you might have been hearing the gas jets in the heater.

Those are the only things near the right rear that I can think of that might be making some kind of noise.

[73shark]

The water heater is on the left (street side) side on mine. Maybe the OP meant right if facing the rear.

The noise might be the bed motor trying to extend/retract if it's a lounge model and the switch is stuck/failing or a wire is shorted. Hard to say w/o being there.

[Protagonist]

Originally Posted by 73shark

The water heater is on the left (street side) side on mine. Maybe the OP meant right if facing the rear.

Or maybe my dyslexia (or is that "aixelsyd"?) is kicking in again.

[73shark]

Bottom line is I can't really think of what might make a noise back there on either side that is cyclical like he inferred.

Edit: Would be nice to know if the noise returns when the 12V is turned back on.

[PSchw]

Sometimes my step motor makes a noise when i turn the engine off. I was told by AS that is normal.

Another noise I lately for us the water pump. Forgot to turn it off and the level was low during driving it sucked air and just kept running. Stopping the engine and hearing the noise which did not stop made me look around. The water pump was hot I turned it of and opens the water it worked fine and the pressure switch turned it off.

[dalemonroe]

I've heard that same pulsating rurrr rurr noise from fans of various types. The plastic blades on an electronics cooling fan can warp and brush the shoud. You either replace the fan or find a way to maintain separation.