Electrical problem

[thewhitehat]

I set up my trailer yesterday, and last night I noticed the air conditioner was having a hard time trying to come on so I turned it off. A few minutes later I noticed the lights in the trailer were very dim. I was also unable to turn on the furnace when it got cold late at night. There is construction going on at the park where I’m at and I was warned that electricity might not be available at times. Today, I brought out my inverter generator and hooked it up and started it up, but it doesn’t seem to have helped the problem with the dim lights and the air conditioner not starting. Also my refrigerator check light just blinks all the time. What’s going on?

[QCMan]

Sure sounds like a bad battery or low/no output to the battery from the converter. Was the battery kept charged while the unit was in storage? The common item is that everything you say does not work has a 12 volt circuit that relies on the converter or battery to work. Checking battery voltage is your first step. Good luck!

[Mike&Sandy]

So, this is interesting to us noobs. There would still be a problem even after hooking up to the generator?

[thewhitehat]

I will say that I put a new battery in recently and then checking the power as it is hooked up to the trailer I noticed it is down to one light, so it is nearly discharged. So I will charge it and see what happens next

[JRTJH]

Originally Posted by QCMan

Sure sounds like a bad battery or low/no output to the battery from the converter. Was the battery kept charged while the unit was in storage? The common item is that everything you say does not work has a 12 volt circuit that relies on the converter or battery to work. Checking battery voltage is your first step. Good luck!

The air conditioner doesn't "get power from 12 VDC"... While the control system/thermostat are 12 volts and operate from the battery or converter, the air conditioner is 120 VAC and the OP's statement, "I noticed the air conditioner was having a hard time trying to come on..." followed by the statement, "There is construction going on at the park where I’m at and I was warned that electricity might not be available at times..."

If the OP doesn't have an EMS, he may find that his issues are a result of a "campground construction issue". It could range from damage caused by the campground power grid "brownout condition" to a "spike/miswired spark condition".....

I'd agree, check the battery and the converter causing the "dim lights", but I wouldn't rule out the air conditioner problem being caused by an issue caused by the campground power grid.

It'll take a bit of troubleshooting to determine what's damaged, and obviously, if the trailer system won't "return to normal" when connected to an inverter generator, there's likely something damaged INSIDE the trailer.

[JRTJH]

Originally Posted by thewhitehat

I will say that I put a new battery in recently and then checking the power as it is hooked up to the trailer I noticed it is down to one light, so it is nearly discharged. So I will charge it and see what happens next

The most common issue with "a new battery that won't charge" is the reverse polarity fuses on the converter. They will "blow immediately" (to protect the converter circuits) if the battery is connected improperly. It only takes a "split second of reverse power" to blow the fuses, so if you happened to touch the battery terminals to the battery cables incorrectly, those two fuses are blown and can cause exactly what you're seeing.

[thewhitehat]

The battery was not connected improperly, not even for a second. Could be a bad converter?

I disconnected shore power and plugged my truck into the trailer like I’m going to tow it and let the truck idle for a few minutes. I noticed a charge of the battery went up considerably and I could start the refrigerator and the lights look normal.

[Steveo57]

The converter is not working or the reverse polarity fuses are blown. Find the reverse polarity fuses and check them out. And check the breaker for the converter is not tripped.

[cavie]

Originally Posted by Mike&Sandy

So, this is interesting to us noobs. There would still be a problem even after hooking up to the generator?

Yes. The fridge, furnace, water heater, A/C all use 12 volts for the control circuit. The furnace is a 12-volt fan motor. The battery needs to be "in use" and charged.

[cavie]

Originally Posted by thewhitehat

The battery was not connected improperly, not even for a second. Could be a bad converter?

I disconnected shore power and plugged my truck into the trailer like I’m going to tow it and let the truck idle for a few minutes. I noticed a charge of the battery went up considerably and I could start the refrigerator and the lights look normal.

A voltmeter will tell you what is wrong. You can not troubleshoot without one.

[wiredgeorge]

If you are camping at a park with questionable power, are you using an EMS?

[JRTJH]

OP,

Rereading your initial post, the first few words may be the answer to your issue:

"I set up my trailer yesterday..."

I'd ask: How was your trailer stored prior to when you "set it up" ???

The reason I'm asking: If your trailer was stored without any power, even with the battery cutoff switch turned to OFF, there is a parasitic drain on the battery and it will be "completely discharged" (that means 0 VDC) and likely wouldn't recover enough charge from the converter to power the system. So, if you "plugged it in, turned on the air conditioner and the lights were dim" You may have a completely dead battery that is permanently damaged and will never be capable of a 100% charge again.

If your trailer is normally stored without shore power, you might consider rewiring the battery cutoff switch so it disconnects ALL of the trailer systems or just remove the battery negative (ground) terminal when you put the trailer in storage.

[thewhitehat]

It was stored without a battery and no shore power because the last battery had died so I bought a new one and put it in yesterday right before I took off. As far as an EMS, I have no idea what that is.

[sourdough]

An EMS is an "electrical management system". You plug it in (or it can be hardwired inside the trailer) and it monitors incoming power for faults including low voltage which you may have experienced. If any of those conditions occur it will shut down power to the trailer to prevent damage to it.....and it will definitely occur if left unchecked. The two favorite brands as it seems are the Progressive or Surge Guard by Southwire. DO NOT get just a surge protector - but everyone should have one. Mine tells me incoming voltage per side (50A), amp usage per leg etc. Don't leave home without one IMO.

[jasin1]

It sounds like you lost one leg of power to ac unit or possibly a bad capacitor if it tried starting on a low voltage condition

[Mike&Sandy]

Well, you guys have scared me enough. The surge guard 34951 was $349 on Amazon today, according to camelcamelcamel, that's the best price for a while.

[cavie]

Originally Posted by thewhitehat

It was stored without a battery and no shore power because the last battery had died so I bought a new one and put it in yesterday right before I took off. As far as an EMS, I have no idea what that is.

https://rvmentor.com/2019/11/24/ems-...-rmNUwmN0s6qLo
0_1M3_i4tQ-P0

[sourdough]

Originally Posted by Mike&Sandy

Well, you guys have scared me enough. The surge guard 34951 was $349 on Amazon today, according to camelcamelcamel, that's the best price for a while.

From memory I believe the 34951 has the optional wireless remote...get it. I'm going to upgrade mine that does not have the remote to that one.

[Mike&Sandy]

Originally Posted by sourdough

From memory I believe the 34951 has the optional wireless remote...get it. I'm going to upgrade mine that does not have the remote to that one.

Yes, that is the only difference that I can find from the 34950, which everyone seems to love.

[sourdough]

Originally Posted by Mike&Sandy

Yes, that is the only difference that I can find from the 34950, which everyone seems to love.

I have the 34950 and I do love it. Want the xxx51 for the remote - and the new ones monitor for a fault inside the trailer (don't remember which one).