RV Electrical Problems

by Geri (Picayune, MS)

Question: We too have battery issues. We are parked at a full hookup site. We purchased our 2004 Sprinter used. When we leave it plugged in to the electric at the RV site, we come back to NO power and empty batteries. Any thoughts on what could be wrong?

Answer: With the limited information, here are a few thoughts. It sounds like maybe the circuit breakers are tripping. Perhaps you have too many electrical draws causing the circuit breakers to trip.

Additionally, your batteries may be bad. It’s difficult to guess, since we don’t know what you have plugged in/running that might be drawing down your batteries. If possible, stay in the RV to see what happens while you are there. You can also read other posts on our site about troubleshooting battery issues.

Power Problem

Question: I just replaced the battery on my 31 foot travel trailer. Now when I go and plug in to my house, I do not get any reading on my monitor for tank levels or battery level. The air conditioner also does not work, but my water pump works and all the lights inside will work. Why would the air conditioner, fridge and the tanks/battery monitor not be working when the trailer is plugged in and with a new battery?

Answer: We can suggest a few things to consider, although it is difficult to thoroughly diagnose the problem remotely.

Here are a few thoughts. If you replaced the battery without turning off all the breakers, there is a good chance that while installing the battery you might have caused an overload which tripped a breaker or fuse. If you have not done so, reset the breakers and check your fuses.

In addition I would also check/reset the co2/propane alarm., in case that is causing the fridge not to work.

You can also recheck the battery connections and make sure you reconnected all those that that were there before to the proper terminals. As a last resort, take your RV to a repair shop.

I would check if you hooked your battery backwards, White wire is negative and Black wire is positive. I know I’ve done it and it sounds like the same problem I was having.

RV Power Bypassing Converter

by Tony (Qualicum Beach,BC Canada)

Question: I want to run a dehumidifier in the winter. I was told I had to leave the batteries in my trailer because the inverter charger would continue to try to recharge them even if they were not installed and I was plugged in to shore power to power the dehumidifier. Is there anyway to get 110 into the trailer and bypass the inverter/charger other than running an extension cord through a window or something like that?

Answer: Not knowing your specific circumstances, we aren’t clear on whether you want to remove the batteries and/or if you have a limited electrical supply while storing the trailer.

But here are a few of our thoughts:

  • If you do remove the batteries, even though your inverter/charger may be on, it will not be drawing much current since the battery (load) is not connected. In an electrical circuit you must complete the circuit before power is consumed. If the battery is not connected, then the charger will be on and drawing whatever it draws while on standby, but not “trying to charge the battery”.
  • You may have an outlet that does not run off the inverter. On our particular RV we do have one outlet that does not run through our inverter. That particular outlet powers our combo washer/dryer. So if we turn off the inverter/charger, it still works off shore power.
    Perhaps you have a similar situation. or you could just run an external extension cord.
  • You may be able to turn off the inverter/charger if you don’t need it for any reason. We have a circuit breaker that turns off our inverter/charger.
  • If you have a three stage charger, you should be able to leave the batteries installed and charging, since the three-stage charger should guard against overcharging. However, it is recommended that you check lead acid RV Battery water levels and state of charge once a month. Use distilled water.
  • Even if you remove the batteries and store them in a cool place, (but not one subject to freezing), it is advisable that you check the stored batteries periodically for water levels and the state of charge.
  • If your batteries are not being charged while in storage, do not let them freeze. They will never recover to hold a charge again.

We highly recommend you check your own specific owners manual and/or contact the manufacturer for direction on how to maintain and store your batteries and how to best store your trailer.

Electric Power Loss

by Debbie (SC)

Question: We have a 1997 Coachmen Catalina Sport. We lose all power while the air conditioner is on and I use the vacuum cleaner, or a small fan. We have it plugged it into the garage outlet (no extension cord) and it trips the breaker to the house. As we are new owners of an RV I am wondering if we will be able to watch TV, make coffee etc. while the air is on. We do not have an owners manual.

Your issue seems to be a power management problem. We suspect that the outlet you plug into is a 15 or 20 amp outlet. The RV’s air conditioner requires a minimum of 15 amps to run; your vacuum cleaner will require at least 6 amps. So you may be drawing more amperage than the house outlet can safely provide and it trips the breaker.

If your camper has a 30 amp power cord, try connecting it to a circuit that has that capacity. If you do not have such a circuit available you will have to manage your power consumption while plugged into your garage outlet. In other words – do not use your air conditioner and vacuum cleaner at the same time. Another option might be to get an electrician to wire a new circuit for your RV.

When you are connected to the proper power supply you should be able to use the air conditioner and one high power draw appliance without much of a problem. The TV draws very little power so that will not be an issue. I would be careful about running the coffee maker all the time, because if you plug in another high power appliance like a hairdryer and start it up, you might pop a circuit breaker. Again this goes back to power management.

Here is a list of approximate wattage draws for common appliances (be careful this is only an illustration and may not be applicable to your specific application)

A/C 1600 – 2500 Watts
Microwave 1200-2000 Watts
PC Desk top 400 Watts
TV 30-300 Watts (depends on size, B&W or Color)
VCR 40-60 Watts
Refrigerator/Freezer 400-1200 Watts
Toaster/Toaster Oven 800-1500 Watts
Hair Dryer 900-1500 Watts

Other related subjects:



We also suggest that new RVers take advantage of some of the great learning resources about the RV lifestyle, such as RV books and videos.

You might also want to contact Coachmen to try to get an owners’ manual and any other specifications they can provide about your model RV.

Removal of Dometic NDR1292

by Harlan S (Palm Springs CA)

Question: I’m installing a residential refrigerator in my 2004 Pace Arrow. I was just wondering what to do with the 12V wires that will be left behind from the old RV refrigerator. I suppose just put on wire nuts, tape, and secure out of the way. Any thoughts?

Answer: That’s what we would do – just cap them with the wire nuts/tape and secure them out of the way. Other comments welcome.

I added a motion light to the DS RR wall using those 12v wires.

In addition to capping and securing the wiring connections, if possible I would pull the breaker or fuse if there is a dedicated fuse for the fridge. If you do that, place a tag on the dead end wires and at the panel stating what you did.

Electrical Question Front Clearance Lights

by Shirley (Alberta, Canada)

electrical question front clearance lights 21739299

Question: This is an electrical question regarding the front clearance lights on an old 1979 Ford/Liberty RV. Friends of mine have purchased a 1979 Ford motorhome. It has a Liberty motorhome on a Ford chassis. Is there a 12-volt fuse box for the lights on the RV? Also, is there a schematic as to how the wires are run on these old RV’s that I can source?

Answer: We cannot say if the manufacturer is still in business so we cannot point you in that direction. However, we can say that all motorhomes have a 12 volt fuse box not only for lights but also other 12 volt appliances.

We invite others to comment in the hopes that someone will add some details or schematics that may be of help to you.

Comment: I assumed there would be a fuse box somewhere in the RV but I looked everywhere. I should add that it says Liberty on one part of the RV & Security on the another area. Was hoping someone knew where the fuse box was located or where the wires run inside.

Losing Power

by Sue (Ontario, Canada)

Question: One part of the power in my trailer goes out several times in an evening:
TV, stereo, lights over the couch, lights in the kitchen, carbon monoxide detector, fridge, bathroom lights and bathroom exhaust fan.
Then after a minute, give or take a few seconds, it comes back on by itself. What would cause it to do this ? HELP

Answer: There could be various causes. We are assuming that you are plugged into 110 power. We are also assuming that part of your list (such as the lights) run on 12-volt DC and the other appliances (such as the TV, Stereo, fridge) are on 110-volt AC.

It could be that something is wrong with your converter or a bad ground. It could also be a loose wiring connection somewhere in the trailer.

You mention that part of the power goes out. It might be helpful in your troubleshooting to consider which appliances, etc. do not lose power. Perhaps this will be a clue as to the source of the problem.

Another thought is that you might have some sort of thermal fuse or breaker that is sensing that a circuit is overheating and automatically shutting down power on that circuit for a few minutes until things are cooled off.

If you have access to the trailer schematics, owner’s manual or can contact the trailer manufacturer, they may be good resources.


Everything that is going out is all on the same circuit and connected to the 12-volt DC(battery). Yes we are connected to 110-power but don’t have a battery in place. After some discussion today, the consensus seems to be that it is the converter. We replaced the convertor and have not had any problems since.

Thanks for the help!