Electrical Issue

[TheSturms]

New Montana owner here. Second fifth wheel owner. Picked up the new 5th wheel Montana 3855br yesterday. Set it to and everything seemed to be working fine. Checked the air conditioning. It worked. Switched the thermostat to heat- electrical and the power shut down immediately. We have no AC power but DC is working until the batteries drained. The breakers never kicked. We checked power at the main electrical meter and it is getting 120v as well as the camper outlet power cord plug. The batteries will charge when only connected to a battery charger such as a vehicle. The inverter power button in the hallway wall now has an amber light and stays lit up. No error code displays unless the battery levels drop then we get the E01 code meaning the battery power is low. We have reset the GCFI on the outlet in the bathroom and behind the tv. That’s the only 2 we can find. Does this seem like an inverter issue? It’s Sunday so I can’t get mobile or tech help to get someone out here. The dealership we just got it from is closed. Just trying to diagnose something today to get me back up and running.

 

[workinonit]

What type of shore power are you connected to? 50A, 30A or 15A? Does the camper have an EMS or are you using a surge device of some type that gives any indication of correct power?

 

[TheSturms]

50 amp. And yes, we have a surge protector on the main electrical bit as for an EMS, not that can I find anywhere.

 

[sourdough]

Sounds like an incoming AC problem. No AC, no converter = dead batteries. Do you have that EMS to tell you the condition of the incoming power or do you have a VOM (multimeter) and know how to use it? What is the arrangement from the power ped to the RV? Does it have adapter/dogbones? A meter will tell you where you lost it.

 

[TheSturms]

I have a 50 amp receptacle on the power ped. A surge protector plugged into that and my RV electrical cord plugged into the surge protector. No additional adapters. I verified the power ped and electrical cord were both getting 120v power. I assume it’s something within the camper due to both of these getting good power. Mind you, I am not an electrician but I live in an RV while I’m working out of state.

 

[flybouy]

Did you try Cycling the breaker for the converter. It's typically labeled Con. Did it just "stop working" or did it stop after a battery was taken and put back in, or some other work was done?
ADDED: DId you check for voltage at the panel INSIDE in the breaker box? Could be the cable isn't carrying the voltage on one leg from the plug.

 

[JRTJH]

You say you're using a "plug in surge protector"... Is it an EMS or a surge protector ??? There is a HUGE difference. You also say that you have verified 120volt power to the cord. Is that "at the surge protector to the cord" or is that "at the trailer connector on the cord" ??? Also, have you positively confirmed that there is not a "hardwired EMS" installed between the trailer shore power plug and the trailer circuit breaker panel ???? The reason I ask is that Keystone last built the 3855BR in 2022, so it may be that your trailer is previously owned ??? I'd suspect that most owners would not operate a Montana, as much as they cost, without the protection of an EMS, either built in or plugged into the pedestal.... Last question, have you attempted to power up the trailer without the plug in surge protector in the works ???

After getting answers to those questions, then we can move on to things like the reverse polarity fuses on the converter.... I'd suspect that if you bought it and set it up "yesterday" that today, the batteries would be dead, assuming the dealership that delivered it might have changed out the battery/batteries for new ones and they may have blown the reverse polarity fuses. If so, the time line from setting it up to the batteries are dead is about 24 hours, so that's a high probability... But we need to know the answers to the first questions before going into other possibilities....

 

[Viper02]

If you verify with a multimeter that you have incoming 120VAC on both legs (Red/Black) wires from the RV pedestal and at the other end of the shore power cord ( if its plug in type and not on cord reel ) then IF YOU HAVE a GENSET PREP there might be a transfer switch that is not operating correctly .. if so then you will not get any 120VAC to the inside power center control box

 

[adeakins]

I have a 50 amp receptacle on the power ped. A surge protector plugged into that and my RV electrical cord plugged into the surge protector. No additional adapters. I verified the power ped and electrical cord were both getting 120v power. I assume it’s something within the camper due to both of these getting good power. Mind you, I am not an electrician but I live in an RV while I’m working out of state.

I have a 2018 3791. Encountered a similar set of symptoms a few months ago. Long story on the diagnostic process made short; the problem was where the power cord (aka; “shore power”) connected into the trailer. One leg was burned with the other in progress. No breakers tripped anywhere. Fortunately we found it in the nick of time.

 

[jaredjohn4]

I had a power problem while on a long trip. I ended up calling a mobile rv tech. He determined that the problem was after using power for a while, the rear connection was getting warmer. Some of the wires pulled back from the inside of the connection and we lost internal power. He said he reconnected the camper plug and then life was good. Sounded strange, but we haven't had a problem yet.