Batteries get neglected when running the heater on electricity

@dsfdogs as long as he's not tripping the breaker at the shore power panel, I don't think it would make a difference.

+1 what @MuttonChops said.

If turning the battery switch off results in no 12V to your Tab, yet the shore power is connected, then the converter is not providing any power to the 12v side.

The fault is probably one of the fuses that @MuttonChops described. The breakers in the power center are only for the 120v circuits, so they can be ignored.

Edit /correction:. 
In a DM, @MuttonChops pointed out :

For the Convertor to 'convert' 120VAC Shore power to 12VDC cabin power at least two AC panel circuit breakers must be on.

The main ACV breaker (far left, 30A) and on most trailer builds the breaker just to the right of the main breaker.

That #2 location breaker is the on/off switch for the Convertor. {again on most builds, some older builds have the convertor connected to the main breaker}

@MuttonChops. Will have to check my own when it thaws out.)

(Everyone else, please correct my thinking here as I’m a little out of my depth with a 400.)

@CruiserCamperChris A couple of things to clarify: First, it’s your *converter* that’s potentially gone bad, not your inverter. They are two different devices, and you’ll want to specify the right one when calling about a repair.

Second, regarding charging before your trip. At 12.15v, you’re at 40% charge right now on those big AGM batteries. Unless you have some spectacular sun directly on that solar panel at the right angle most of the day all week, you may not be able to count on those batteries being fully charged. It takes time for that to happen. Driving will not charge them if your converter isn’t working, as current from the alternator goes through the converter. (Corrected, see post below. Two hours drive time may or may not add much charge, depending on your setup.) Solar is directly attached to the batteries and bypasses the converter.

Here’s where I’m a bit blind, because the 320 batteries are much more accessible. If you can access the battery terminals, you can charge them via a portable charger while you still have access to 120v power at home (NOCO & Schumacher make good ones). These can be attached via alligator clips, or if there’s an SAE port to attach solar panels, adapters are often available for that. This would at least put a solid charge on the batteries in the meantime. Hopefully other 400 owners can advise on the feasibility of this with your model.

As far as repairs go, I’d suggest Googling for a mobile RV repair in your area. Replacing a converter is a very common job (we likely have a few folks here who could walk you through it if you’re at all handy), but using a mobile mechanic is likely to get you on the road a lot quicker than waiting on a dealer to fix the issue. 

rfuss928 said:

VictoriaP
The 12v line from the TV does not go through the converter.  It is a direct connection to the battery (through the 30A in-line breaker).  The TV will charge the batteries through the trailer pig tail if it is wired properly.

Good to know, will edit post. I’m assuming just two hours of drive time likely won’t add a ton of charge to the two big AGMs unless there’s a DC-DC charger installed though, yes?

CruiserCamperChris said:

Thank you VictoriaP. I was planning on adding an SAE lead to my batteries anyway. I have one on all my vehicles so that i can easily out them on trickle charge. Plus, i might want to plug in my suitcase Renogy solar panel sometimes. Thanks for straightening me out about the converter and the inverter. What is the difference? One converts from 120 to 12 and the other inverts from 12 to 120? Are they both in that big black panel near the floor that holds the breakers and fuses? I have a mobile RV repairman coming Monday.

Oh, excellent, glad you found a repair person!

Yes, the Converter is converting 120v from your 30 amp power cord to 12v to charge your batteries.

Inverter “inverts” that process, producing 120v from your batteries for certain outlets on your trailer. As I have a 320, I’m not sure where the inverter is on a 400, but I’m sure someone else here does.