Power Loss

[Cmpurkey]

We have our RV plugged in and after a while we lose power. It won’t suddenly go out like a blown breaker, it starts going dim like low battery. How is that happening if we are plugged in?

[16ACE27]

Plugging in gives you 120 VAC power
Your batteries provide 12 VDC power

So when you "lose power" what is happening? What works, what doesn't?

From your vague description it sounds like the DC loads (like lights) are dimming out indicating that your batteries are supplying the DC loads instead of the converter; which should since you are plugged in.

What are you plugged in to?

What Year/Make/Model RV do you have?

[Grumpy Grampa]

Make sure the use-store switch is in use.

[Cmpurkey]

Originally Posted by 16ACE27

Plugging in gives you 120 VAC power
Your batteries provide 12 VDC power

So when you "lose power" what is happening? What works, what doesn't?

From your vague description it sounds like the DC loads (like lights) are dimming out indicating that your batteries are supplying the DC loads instead of the converter; which should since you are plugged in.

What are you plugged in to?

What Year/Make/Model RV do you have?

The overhead air will stop, the lights go dim and eventually go out. The refrigerator light will go out as well. We are plugged in to an outlet at our house which is on its own breaker. It’s a 30 amp plug.

What would make the batteries be the supply source if we are plugged in?

We have 2013 Thor ace 29.2


We just bought it last week so we are new to all of this!
Thank you!!

[JimOIB]

Does the same thing happen when you are on generator power?

Check the converter breaker in the power distribution center. It should be a 15amp breaker. Make sure it isn’t tripped. Even if it looks ok turn it off then back to on.

[16ACE27]

Originally Posted by Cmpurkey

The overhead air will stop, the lights go dim and eventually go out. The refrigerator light will go out as well. We are plugged in to an outlet at our house which is on its own breaker. It’s a 30 amp plug.

What would make the batteries be the supply source if we are plugged in?

We have 2013 Thor ace 29.2


We just bought it last week so we are new to all of this!
Thank you!!

When you say "overhead air" are you referring to the air conditioner or the vent fan?
When all this happens, is the clock on the microwave still on?

It definitely sounds like your batteries are going dead. When plugged in to SP the converter should be supplying DC loads and charging the batteries. Possible causes of the problem are:
SP isn't making it to the converter
The converter breaker is tripped
The converter is bad

The microwave status helps eliminate the first cause
You can check the converter breaker to eleiminate the secound cause

[Jimbo56]

We had this happen in a 5th wheel. Converter was bad.

[Cmpurkey]

Originally Posted by 16ACE27

When you say "overhead air" are you referring to the air conditioner or the vent fan?
When all this happens, is the clock on the microwave still on?

It definitely sounds like your batteries are going dead. When plugged in to SP the converter should be supplying DC loads and charging the batteries. Possible causes of the problem are:
SP isn't making it to the converter
The converter breaker is tripped
The converter is bad

The microwave status helps eliminate the first cause
You can check the converter breaker to eleiminate the secound cause

The breakers and fuses are good. The light comes on to microwave but no display and it won’t run. It was the a/c that was running. I’m thinking that every time it’s been plugged in, it was assumed that it was running off of SP but it’s really been battery. Now that we have bought it and have had it on for several hours, we are seeing there’s an issue.

[JimOIB]

Please try the generator and see if things work. Unplug from shore power first. This will help narrow down the problem.

Curious, when you say 30a plug is it an RV plug or something else? It would be nice to know how you are actually connected to shore power.

[Cmpurkey]

Originally Posted by jimbo12

Please try the generator and see if things work. Unplug from shore power first. This will help narrow down the problem.

Curious, when you say 30a plug is it an RV plug or something else? It would be nice to know how you are actually connected to shore power.

We have a dedicated 30amp single pole breaker. Our rv cord is plugged in to that.

[16ACE27]

Originally Posted by Cmpurkey

The breakers and fuses are good. The light comes on to microwave but no display and it won’t run. It was the a/c that was running. I’m thinking that every time it’s been plugged in, it was assumed that it was running off of SP but it’s really been battery. Now that we have bought it and have had it on for several hours, we are seeing there’s an issue.

he A/C can't/doesn't run off the batteries. It WILL stop when the batteries die because of loss of control power from the thermostat. My crystal ball says you have a bad converter.

[Cmpurkey]

Originally Posted by 16ACE27

he A/C can't/doesn't run off the batteries. It WILL stop when the batteries die because of loss of control power from the thermostat. My crystal ball says you have a bad converter.

That’s what I was afraid of…. We were supposed to head out Monday.

Thank you for your help!

[JimOIB]

Originally Posted by 16ACE27

he A/C can't/doesn't run off the batteries. It WILL stop when the batteries die because of loss of control power from the thermostat. My crystal ball says you have a bad converter.

Hey ACE - what about the ATS? The microwave has a light but won’t run and that’s 120v all the way. A simple running of the genset would eliminate the ATS. Fire up genset, microwave should work and if the batteries are low the converter fans should come on. Worth a try? Otherwise my OCD rain-man thing is going to keep me awake all night.

[16ACE27]

Originally Posted by jimbo12

Hey ACE - what about the ATS? The microwave has a light but won’t run and that’s 120v all the way. A simple running of the genset would eliminate the ATS. Fire up genset, microwave should work and if the batteries are low the converter fans should come on. Worth a try? Otherwise my OCD rain-man thing is going to keep me awake all night.

The fact that the A/C works, but dies after a while pretty much eliminates an ATS issue unless the contacts are heating and "opening" due to high resistance. But if that is the case the lights would not go out or dim until log after the A/C (and other AC loads) quit - unless the batteries are so weak that as soon as the converter shuts off they drop to 10 volts and continue to head south.

I can't comment on " The light comes on to microwave but no display and it won’t run" as every microwave I have ever had, had no light and you knew it got power because the display came on - zeros until the clock is set.

[JimOIB]

Originally Posted by 16ACE27

The fact that the A/C works, but dies after a while pretty much eliminates an ATS issue unless the contacts are heating and "opening" due to high resistance. But if that is the case the lights would not go out or dim until log after the A/C (and other AC loads) quit - unless the batteries are so weak that as soon as the converter shuts off they drop to 10 volts and continue to head south.

I can't comment on " The light comes on to microwave but no display and it won’t run" as every microwave I have ever had, had no light and you knew it got power because the display came on - zeros until the clock is set.

Got it. I think your crystal ball is pretty clear.

[16ACE27]

Originally Posted by jimbo12

Got it. I think your crystal ball is pretty clear.

If I could only get the "mind reading" add-on to work.

[Jimbo56]

Originally Posted by Cmpurkey

That’s what I was afraid of…. We were supposed to head out Monday.

Thank you for your help!

When this happened to us on the road, I bought a 30 amp Dewalt battery charger from Home Depot. Plugged it into the 20 amp plug on the pedestal at the CG. The charger powered the 12v. The 30 amp plug powered the 120v. This setup allowed us to complete our trip.

[JimOIB]

The one thing not eliminated yet is the battery. I assume the coach has a WFCO dist center which has current limiting shutdown protection. A battery that wont take/hold a charge would draw high current from the converter and over time shut it down. Simple test, disconnect the battery from the coach with battery disconnect use/store, on/off, whatever switch you have and hook to shore power leaving the battery disconnected. If things don’t work correctly then the converter is bad. If things do work correctly then have the battery tested/replaced. Your statement about the coach being new to you this week stuck in my brain. My OCD wouldn’t let me leave this be. Sorry.