Power Problem Refrigerator & Int. DC Lights

[leonardbarney]

I own a 1996 Newmar Dutch Star diesel pusher which I purchased about two years ago. I thought the house batteries were weak and inspection revealed the four batteries were not from the same manufacturer but they were still doing the job and we never dry camped so I went with them.

Before a trip I would bring the coach home and plug our home 120 AC into the plug behind the fridge panel on the exterior of the coach. The idea was to cool off the fridge before hitting the road. Once on the road the fridge kept cool with the propane gas. The last time I tried to use the 120 AC from our home to the fridge, the fridge would not come on with the AC or gas. No lights on the fridge door panel at all. I replaced the four house batteries and the fridge and interior DC light still don't work. The fridge and interior light come on if I run the generator. I suspect there is a fuse of some sort which has blown. Any idea where it might be on my coach if I happen to be right??

[wolfe10]

Leonardbarney,

Welcome to the FMCA Forum.

First thing I would do is use a digital voltmeter (they start under $10) to check voltage at the batteries and then at the back (outside access door) of the refrigerator.

Very rare for the refrigerator DC to go through the salesman switch/main switch by the door.

There should be a fuse for the refrigerator-- if battery voltage is 12+ VDC, and no voltage at the refrigerator, locate the fuse. You may need to check with Newmar if you can't find it.

What converter, charger or inverter/charger do you have? Just wondering if you can use your home outlet to charge the batteries?

Brett

[leonardbarney]

Brett,

The coach had a converter/inverter but the dealer removed it stating it had gone bad. We didn't replace it because we can start the generator when we want coffee or something. BTW, there is a solar panel on the roof which seems to be working, the gauge on the wall indicates it's working.

Len

[wolfe10]

Len,

The generator will not directly charge the batteries. The 120 VAC power from either shore power or generator are used to power whatever device you have to charge the batteries.

When he removed the inverter/charger, what replaced it. When you are plugged into shore power for a week, what keeps the batteries up (other than a solar panel)?

[dickandlois]

Hi Len, Welcome to FMCA!

The 12 volt system batteries should charge off the Engine Alternator directly or through a battery isolator, even if you do not have a Charger / Inverter.

Brett mentioned measuring the voltage across your coach batteries with a meter. What kind of reading do you get across the coach and chassis batteries with and without the engine running?

The voltage at the refrigerator control board needs to be above 10.5 to 11volts for the refrigerator to run on LP or AC.

Could you post the make and model of your refrigerator for the group?

Rich.

[leonardbarney]

I have never had a problem with the light or anything else in the coach that runs of 12V before so I think it must have charged while attached to shore power. I forgot to mention that I the holding tanks panel is also out. I don't have room to keep the coach at home so I need to go to the storage area and do the measurements and get the make and model of the fridge. As far as I know nothing was installed to replace the charger/inverter.

[dickandlois]

Len,

I have been reading and rereading your post. You did mention that you had lights and refrigerator light when the generator was running and on shore power no lights. Correct?

I'm wondering if that is the case if you switched the shore power / Generator switch and its in the generator position and not the shore power position.

You also changed out the batteries, Correct? If that is the case did you get one of the battery parallel or series jumpers on a wrong terminal? That could be causing the problem also.

When you get to the coach check the wiring and measure across the points that should read 12 volts.

Rich.

[kaypsmith]

Do the interior 12 volts lights and the storage water pump work without the generator running?

Kay

[leonardbarney]

I am sure the batteries are wired the same as before we installed the new batteries.

I am sure the 12 volt and 120 volt systems all work with the generator and shore power. I'll be camping with the coach next week and can confirm this than.

I am not sure about the water storage pump, I didn't try it but I will when I get the coach home next week.

The refrigerator works and cools when the generator is on, the house 12 volt lights work when the generator is on. Next week I can confirm whether both work with shore power.

I have never heard of a shore power/generator switch. Where might I find it?

[wolfe10]

A "shore power/generator switch" is also known as an ATS-- Automatic Transfer Switch.

You can only use one source of 120 VAC at a time-- either shore or generator, not both. The ATS disconnects one when the other is turned on. Generally, the generator is the "favored" source.

But, it sure sounds like you have a problem between your battery and main fuse box, since 12 VDC things do not work unless your charger is supplying 12VDC.

Use a digital voltmeter (start under $10). Shore power off, generator off. Check voltage at the battery-- positive to negative terminal. If 12+ VDC, keep going toward the main fuse box. Determine where you go from 12+ VDC between the positive side and any good chassis metal/ground. First place I would look is any large fuse or fusible link.

[dickandlois]

Len,

Brett, mentioned the ATS switch / Relay that transfers power from ether the generator or shore power. There is a possibility of a ATS failure, but you need to check and see if you have AC and DC power when on either shore or generator power.

Some coaches have a manual (push button) switch(s) that control solenoids located near or in the entryway to disconnect the coach and chassis batteries from the circuit panels. Often the switches get bumped unknowingly and the circuit is disconnected.

Others have rotary switches in or near the Coach and Chassis battery bays that disconnect the batteries.

Should the chassis circuit be open, then you would not be able to start the coach or generator in many cases. Should the coach disconnect circuit be open then you would not have 12 volt power to any of the low voltage circuits.

Should you have 12 volts when on shore power or when the generator is running, there has to be a 12 volt charger or source coming from somewhere.

The switches can be named, Main and Aux., Chassis and Coach, Ship and shore; in some cases one manually selects

where the 120 volt AC is being supplied.

Rich.

[leonardbarney]

OK, got the coach home today and checked the wiring in the shore power cabinet.

I was just looking to see if anything looked like it shook loose or something. While checking I saw a faded strip of paper attached under a set of wires going to a number of little black boxes each about a inch long and 1/2 inch wide. The strip of paper said reset button for house and fridge on top or bottom. It was actually on the left side and when I pushed it in the lights and fridge now work. It seems the problem is solved.

I think I just got dumb lucky because I know very little about electricity and testing stuff. Thanks very much for all of those who were trying to help. I am wondering if the dead house battery may have tripped the reset switch somehow.

Len

[dickandlois]

Len,

Thanks for posting the answer!!

Now we are all a little smarter! Hum!! Now can I remember what filling cabinet I put it in !! LOL

Rich.

[desertdeals69]

If it trips again you need to trouble shoot it and see if its the breaker or the circuit is drawing too much current.