Dometic DM2652

[DenverCZBob]

Before I have to drive all the way back to the dealer to get it checked, I thought I would see if anyone has ideas on what I may be able to do.
We took our 238ML up for our shake down trip(Jefferson Reservoir, Altitude 9,900ft). Everything ran great but the Fridge. Both nights during the night at some point the "Check" light came on. We got up in the mornings and simply turned the fridge off, then back on. It took a few minutes but re-lit and ran all day. Brand new full LP tank(the furnace had no issues and was running when we got up till we shut her down). Battery was no problem at all, was still at 90% when we went home(2 Trojan T-105's). I see the manual says to always run the fridge on AC above 5,500 ft. Do you think it could be as simple as that?

Thanks,

-bob

[chuckster57]

I downloaded the owners manual and I couldn't find anything about using A/C above 5500 ft.

Try it at a lower elevation and if it works just fine, then there may be something to the elevation caution.

[DenverCZBob]

Thanks Chuckster. I'll test her out this weekend at home. Still around 5600 ft but thats as low as I can get:).

-bob

[B-O-B'03]

We camped at the collegiate peaks campground, east of the cottonwood pass, elevation was 9770 some odd feet and ran the fridge strictly on gas, other than the few times we ran the generator and it worked fine.

I was blissfully ignorant of any elevation limitations to the gas operation, but that could be a pain for the type of camping we generally do :( (State/USFS/BLM campgrounds, with out hook ups)

Will have to keep that in mind, next time out.

-Brian

[DenverCZBob]

I'll start the fridge up tomorrow after work on propane and let it run over night and report back.

thanks,
-bob

[DenverCZBob]

Well I started it up. It ran for about 10 minutes and then I got the check light. Shut it off and then back on. I checked it before I went to bed (about 6 hours later) and it was still running. I got up this morning and the check light was on. Bummer. I guess I will be calling the dealer tomorrow.

-bob

[Festus2]

There is a warning about altitude's effect on the operation of some Norcold fridges and it does state in the Owner's Manual that you may run into difficulties at altitudes higher than 5500 ft. It seems that most Dometic fridges do not have a similar warning and do not experience the same kinds of problems in higher altitudes.

I believe that propane fridges can be adapted by adjusting the size of the orifice to allow them to operate more efficiently at higher altitudes. It would make sense that, because of the lower oxygen levels at higher altitudes, anything that operates on combustion would be affected and some adjustments might be necessary.

Portable propane heaters such as Mr. Buddy also have mentioned that altitude may have an effect on the heater's operation. While most users have not had problems some have and have had to replace the orifice with a different size that allows the heater to function properly.

[sourdough]

Some propane appliances are very picky about altitude. Bought a ProCom propane log heater for our home in the NM mountains (9000 ft). It would not work. The local propane dealer said that particular brand had problems with altitude. Took it back to our TX home (3500 ft or so) and it ran perfectly; took it to Goodwill.

[polaris_rider]

I have had some experience with issues similar in my last tt. It could be the elevation. Does the fridge work on propane consistently when you are at lower elevation? Is the stove near the fridge? Light the stove and see if there is consistent flow of propane. I had one tank where the valve was having issues and anything running on that tank would not work properly. If there is air in the line or you have a tank that sputters, the fridge will not stay lit.


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[DenverCZBob]

The stove is next to the fridge. I always prime the line from the stove. No issues that I could see with gas or 12 volt power. The fridge ran for quite some time before the check light came on. It performed the same at 9900 feet camping as it did in our driveway at 5600 feet or so...ran for a while(many hours) and then at some point in the night, check light came on.

Here is my latest info. I downloaded the service manual and am hoping that the manual is just a little out of date. It shows a picture of the spark electrode, burner tube etc...well looking at my set up I sure as heck don't see a thermocouple above the burner tube. Did they incorporate that into the spark electrode perhaps?
I guess It's time to actually call the dealer.:(

-bob

[DenverCZBob]

Well I have an appointment in early Aug with the dealer. In the mean time i thought i would clean out the burner tube and assembly and just give the area a good cleaning. It ran all night last night and seemed to fire up instantly were as before seemed to struggle for a couple minutes. I'll run it again tonight and see how it goes.

-bob

[DenverCZBob]

Well it was still running this morning. I was ready to assume victory, but after I went back into the house and took a quick shower, came back out, the check light was on.
Oh well, it needed a cleaning anyways.
Will report back after the dealer appointment..

-bob

[chuckster57]

And I was just about ready to congratulate you.

[DenverCZBob]

Ok, latest update on this.
Took it to an rv dealer(Closest to me), not the dealer who we bought from.
They 'tested' it by plugging into shore power and running on propane for 24 hours and the fridge ran fine. No check light came on.
I told them we did not have shore power camping and so they said it was probably a low battery. (I checked my battery during our first two trips with a DVM several times and it never got below 12.63 volts), I mean come on, these are two brand new Trojan T-105s.
Now I do have to say I only used a "BatteryMinder model 2012" to charge them when I first bought them. The dealer said not to use those unless the battery is already fully charged. So ok, I went out and bought a 70 dollar, 15amp Schumacher 6/12 volt battery charger that does standard, AGM and Gel batteries and charged each 6 volt battery separately over a few days. Hooked them back up in my trailer(not plugged into shore power) and turned on the fridge at 10 am on Saturday morning. It ran all day and into the night. In the morning the check light was on. I also checked the battery voltage (with two separate DVM's every few hours and also in the morning. This time never dropped below 12.65 volts(that was the reading on Sunday morning after I saw the check light.
So now I have it plugged into shore power, running on propane of course and am going to see what that does for a day or so.
Frustrating!

-bob
-bob

[Javi]

Since this is a propane related incident, has anyone checked the regulator, switch over valve and pigtails... and hooked up a manometer and checked the operating pressure at the fridge...

[DenverCZBob]

Thanks for the reply Javi.
Here is what was on the work order sheet.
"Set up unit operated refrigerator on LP for 24 hours, no problem found. Checked all operation unit is working as designed at this time.
Refrigerator diagnose w/pal tester Dometic"
It does not say that they ran it plugged in to shore power but they verbally told me that is what they did. I also have wondered if it was somehow maybe caused by the regulator/LP issue. If the check light comes on during my latest test I will probably try a different regulator to see if that helps.
I have it plugged in to shore power right now(but running on LP).
Does anyone know if the fridge electronics gets 12 volt electricity differently when it is running on battery only as opposed to being plugged into 120ac?
Thanks again,

-bob

[SteveC7010]

Does anyone know if the fridge electronics gets 12 volt electricity differently when it is running on battery only as opposed to being plugged into 120ac?
The 12vdc circuitry is the same all the way back to the battery. The only thing that will affect this is the output of the convertor when running on shore power. If the battery is a bit low, the convertor bumps up the voltage.

It would be a good idea to put a voltage monitor on the line to the fridge.

[DenverCZBob]

Ok, so here is where I am at now. Like I stated earlier I had it plugged in to shore power running on LP. It ran fine for two days. Tuesday night I shut everything down, un-plugged from shore power and started it back up on 12 volt only. Wed morning the check light was on. Wed evening I came home and started un-plugging wires off the circuit board. I checked the power coming from the battery, it was the same as the reading at the battery(12.63). Plugged all wires back into board, started up fridge on DC only and it has been running ever since with no problem! It's now Saturday morning. I checked the battery voltage, 12.5.
Do/did I have a slight bad connection to the board on a wire? Maybe a cracked trace that is now closed because of all my pulling on the wires/board on Wed?

I just gotta laugh :)

-bob

[chuckster57]

No telling what happened, but as long as it's working... maybe you released the gremlins when you disconnected the wires. :eek:

[DenverCZBob]

That's what I am hoping :)
Thanks for all the replies during my ordeal guys.

-bob

[DenverCZBob]

Thought I would update this in the event it helps someone else.
Our first trip this year in the Colorado mountains (about 10,000 ft) and the fridge was back to the same old.
Check light coming on at different periods. maybe last 10 minutes, maybe a few hours.
Did not want to drive it all the way back up north to the dealer only to have them tell me the fridge is fine and runs great when plugged in on AC :). Of course our batteries were always checking at 12.4 v or above but i digress...
I decided to buy the after market board by Dinosaur. Went back to the same campsite this weekend and the fridge ran great. No check light other than the very 'dim' check light that Dinosaur says is normal and has to do with dealing with smart and dumb eyebrows. Got to the camp at 2:00pm on Friday. We used lights, fan water heater anytime we wanted. Didn't use the gen until Sunday morning because DW wanted to use the AC drip coffee maker. Before turning on the gen the volts read 12.4 and the fridge was doing great.
Going up again in a few weeks or so to same area. Will give a quick report after.
Thanks again for all the info and effort you guys provided!

-bob

[Tom N OH]

Seeing as how the one common denominator was that the fridge was running on LP, my question would be whether your LP cylinders were ever properly purged prior to the first fill. In the higher elevations & at night when the temperatures drop, moisture in your LP cylinders could cause regulator freeze ups. Read this article & be informed.

http://home.earthlink.net/~derekgore/rvroadiervfulltimingwhatisitreallylike/id45.html

[DenverCZBob]

Thanks for the link Tom.
I will check it out.

-bob

[hankaye]

Howdy All;

Sure would have been nice if the fella that wrote the article
in the link would have thrown in a few photos to show exactly
what it was he was referring to, otherwise not to bad.

hankaye

[DenverCZBob]

This will be my last post on this unless something changes.
We went for our third trip this camping season and the fridge with the new Dinosaur Board worked flawlessly. Did not use our generator at all,(we added a new electric tongue jack even), lowest our batteries read was 12.3 during lights and fan use.
Hope this helps someone else with similar problem.
Thanks to all who replied!

-bob

[Bill K]

The fridge problem is linked to the gap between the propane gas orifice and the burner tube assembly. The gap is too great and when we camp above 5500' I had the same problem. The propane gas boils off too quick when the atmospheric pressure drops. Not enough gas to ignite. It's all related to Boyle's Law. I fixed it by placing a 3/8" long sleeve on an adjustable wire and securing via an existing screw on the jet orifice assembly. It guides the gas to the burn
er tube. An hour fix. AC pwr above 5500' - that's why so many use those dumb loud generators all day.