12v Concern

[Bob & Debbie]

Have 2018 Montana 3561RL - in storage with no shore power.

Put in new batteries and have power to operate jacks and slides but have no 12v power to lights, vents or the tank & battery level indicating panel.

Any thoughts???

[Mikendebbie]

There is a red "key" switch inside the convenience center. Make sure that is on.
The red switch in the battery compartment is for the residential fridge inverter.

I store my unit at my house and it is always plugged into shore power. Many folks here on the forum install a battery disconnect switch on the negative pole if they store the unit at a storage yard. This prevents the batteries from running dead.

[Bob & Debbie]

Thanks - both switches are in ON position. Batteries not stored in RV - just installed new ones.

[jimcol]

There has always been much confusion on the battery disconnect switch. Don't get hung up on, on or off. Put the switch in the position where the key cannot be removed. That should pass 12vdc power for everything in the coach.

[AZ Traveler]

The self resetting c/b off the battery feeding the coach could have failed. Easy to check with a voltmeter.

[Bob & Debbie]

Thanks - where would that be & what would it look like?

[Bob & Debbie]

Thanks - it is in the ON position.

[AZ Traveler]

Bob,

In my case it is the c/b in the lower right behind my batteries. The larger c/b is for the hydraulics.

[Bob & Debbie]

Zack,

Thanks for the picture - I'll check it out next trip to storage area.

[jimcol]

Originally Posted by Bob & Debbie

Thanks - it is in the ON position.

Whatever position it is in when the key won't pull out is when the 12vdc will pass on to the resettable circuit breaker others have suggested.

[Bob & Debbie]

Jim

Thanks - got the switch in the ON position but no power - will check the breaker next.

[Carl n Susan]

Originally Posted by Bob & Debbie

Jim

Thanks - got the switch in the ON position but no power - will check the breaker next.

Please do all of us a favor! Try to remove the Red Key and tell us if that happened or not.

In the convoluted logic of Montana, the "On" position means the disconnect is in effect (aka ON) and no charge is going to/from the battery (other than the leveling system and other parasites). Leave in in this position for a few weeks and then the batteries will be dead and then nothing will work.

[Bob & Debbie]

Carl,

The key cannot be removed in its
current position.

[Carl n Susan]

Thank you. That was the answer we were looking for. I doubt is it a 50 amp self-resetting breaker issue as the hydraulic pump works. It and the feed to the fuse panel all come off the same side on the CB. Therefore if the pump works, then there is 12V to the converter/fuse panel.

You didn't happen to install new battery recently and accidentally hooked it up backwards, no matter how shortly?? That will smoke the reverse polarity fuses in the converter. I seem to recall there is no power then to the fuse panel and rest of the coach.

[Bob & Debbie]

Carl,

I do have new batteries but had no issues when installing them.
Have no power to the tank and battery level indicating panel, no power to lights and none to the vents - don't know about the fuse panel.

[BB_TX]

Using a voltmeter check that you have +12 vdc on both terminals of all your auto reset circuit breakers near the battery. One of those feeds the battery disconnect switch which in turn feeds those items not working, including the fuse panel. Unusual for that breaker to fail, but yours would not be the first.

[Bob & Debbie]

Bill,

thanks - will check it next trip to the storage area. Too hot here now to be doing much of anything. Hope to get back to the problem this weekend.

[bcrvman]

Originally Posted by Bob & Debbie

Bill,

thanks - will check it next trip to the storage area. Too hot here now to be doing much of anything. Hope to get back to the problem this weekend.

I hope you aren't leaving the battery connected without shore power, a lead acid battery will be dead in a couple weeks due to parasitic draw even when the key is out. Take the battery cable off the negative lead if you are not going to connect to shore power. If you can't connect a battery maintainer, then disconnect the battery and take it home and leave it on a maintainer, note I did NOT say trickle charger. Very different.

[jeririgged223]

I know this sounds crazy but without fail when this happens in mine it's usually a tripped GFI in the bathroom. Sometimes it gets tripped and sometimes it's been bumped during cleaning. Check the GFI

[bcrvman]

Originally Posted by jeririgged223

I know this sounds crazy but without fail when this happens in mine it's usually a tripped GFI in the bathroom. Sometimes it gets tripped and sometimes it's been bumped during cleaning. Check the GFI

I am curious how a 120VAC GFI affects your 12VDC system.