S2RV possible battery issue

[Leon]

I have 2019 Senaca 37k just wondered I here this faint motor noise after I shut my unit down turn off main power switch that controls the RV part and get out to park it for awhile in storage
After shutting drivers door and lock about 5 minutes later this buzzing noise is heard .I am in the country very quiet place other noises easily drowns it out so anyway
The noise I think comes from BULK HEAD MODULE or ECM in picture,located on the firewall on drivers side under hood .Freightliner dealer had suggested it was purging from the DEF .Well when I disconnect the chassis battery it goes away .Also when I open the drivers door it goes away but lights stay on when door is open.Finally when I remove the BHM-V batt 1 30 amp fuse ( picture) and the noise goes away so that’s what I do now when I a parked awhile.
I did take in to the local dealer they were too busy had to wait a month .So I finally get to dealer they said they check it later.The motorhome sat a week after that then the dealer looked at it for an hour definitely said there is a problem but didn’t have a solution parked it outside .for another week 🤔...Anyway I told em I bring it back some other time because I needed to use it So if you own one of these babies listen for that noise or maybe you have low battery situations sometimes 😡

[Youtalken2me]

I realize you posted this back in 2019 but was wondering if you ever found out what the motor sound was when you turned off the coach battery switch? I had the same noise that I recently noticed while we were boondocking in the middle of nowhere. Turns out it is, in my case, the fans in the 12v-120 inverter located in the first bay behind the battery compartment on the drivers side.

I could only hear it in the quiet of Mother Nature in the middle of nowhere

[Leon]

Yes sounds like a good find.. my concern was the fan would never stop my inverter was turned off the truck was parked for weeks so I pull out a fuse under hood to stop it engine compartment while in storage thus no dead battery after a couple weeks or so so no problem after that never spent much time searching. Funny the fan in the inverter if it was left on maybe but if the inverter is turned off which would stop your fridge from running draining house battery .i think mine was more to do with chassis circuit I pulled a 10 or 20 amp fuse can’t remember circuit it was because I sold it few years ago .I am confused that inverter is house battery not chassis battery which my concern was about

[Leon]

Re thinking that the fan noise was in the dash between the firewall nothing from inverter .Frustrating but wasn’t worth the time to tear down the dash and firewall so I just as easy to spend a few seconds yanking the fuse than didn’t worry me

[Youtalken2me]

Ok, I had read your post from 2019 a while ago and then heard that fan noise while boondocking close to a river in Tennessee. I took me a few hours of searching because it sounded like it was coming from behind the driver's seat.

Have a great day and thanks for responding