AC’s and water heater set themselves to Off

[Mikem610]

We have a 2017 Venetian and lately the AC and Water heater have been setting themselves to off. The set temp has been going 71 (normally set to 78). This usually happens overnight, when the temperature drops overnight. No circuits are popping. Any help would be appreciated.

[Skip426]

Are you in a park on shore power ? Or boondocking ?

New to you RV , or one you've had for a while ?

Coach batteries load tested ?

[Mikem610]

We’re on shore power and the house batteries were replaced a year or so ago. We’ve had this RV and have been full timers for 4 years. The coach batteries have not been load tested.

[ProfessorHi]

Originally Posted by Mikem610

We have a 2017 Venetian and lately the AC and Water heater have been setting themselves to off. The set temp has been going 71 (normally set to 78). This usually happens overnight, when the temperature drops overnight. No circuits are popping. Any help would be appreciated.

Did this behavior start recently? Reading carefully, I'm assuming that everything was working and now the set temps are resetting themselves?

What is happening is that the PMM module is being power cycled, either by an external source or doing so by itself. This would affect both the climate temps and the water heater turning itself off.

The PMM (Power Management Module) is located in the curbside rear external compartment. It's black, around 9" square with a solid green LED light located near the inside battery cable attached to it.

1. I would recommend first checking the two battery connections on the PMM with a 10mm socket. First remove both battery lugs to do a true PMM power cycle then reattach the lugs. This just may do the trick since there is usually no other way to truly power cycle the PMM.

2. Then check to see if there is any self resettable inline fuse between the battery bank and the PMM. Change it if #1 did not resolve the issue. Thor may be able to assist you on this one.

Feel free to PM me if these do not resolve the issue.

Melvin w/ Firefly

[Mikem610]

Thanks, I believe I have it resolved. When you said resettable in,one rise, it made me remember a relay I replaced a few years ago. The relay is used to shut off the 12 volt for the entire rig for storage. I turned it off and on again, and the issue is gone. My thinking is the relay was letting the 12 cut and reset for a microsecond. Maybe the relay is getting weak. Or turn off the power reset the firefly system. Thanks for the second set of eyes.