Strange one, some pump kept running

[landmannnn]

I took at 10 minute trip yesterday. When I got back I didn't lock the vehicle.
I noticed about an hour later that I could hear a faint whine from the engine compartment. Some electric pump I presume.
I came back a couple of hours later and the noise was still there. The battery had dropped to 65%.
I then locked it and the whine went about 10 minutes later.
What do you think, just a random gremlin?

 

[JKAlpine]

I’m sure it’s a fan not a pump. It’s normal for them to run a while but not that long. Random gremlin is my guess.

 

[Clark Kent]

I took at 10 minute trip yesterday. When I got back I didn't lock the vehicle.
I noticed about an hour later that I could hear a faint whine from the engine compartment. Some electric pump I presume.
I came back a couple of hours later and the noise was still there. The battery had dropped to 65%.
I then locked it and the whine went about 10 minutes later.
What do you think, just a random gremlin?

Just to confirm, you know the noise the auxiliary cooling fan in the front right wing makes and this was different? I would not call the noise the aux cooling fan makes a gentle whine

The B57 and B58 both have an electric coolant pump controlled by the DDE/DME respectively. This is additional to the mechanical coolant pump. It's not well documented what the electric pump does. It's the electric pump which gets activated during the cooling system bleed procedure.

It's not uncommon to hear the pump running briefly after shutdown but it shouldn't keep running for hours. If you get that again it's indicative of a temperature sensor, harness or a connector (loose, dirty, oily) issue, or potentially a pump fault. Perhaps check for a code if you have access to a reader.

Here's an example of the electric coolant pump operating (Reddit). This one sounds like a bilge pump.