Dometic DMR 7-series problem

[Cowracer]

New camper, first trip out. Fridge worked fine on shore power at home. Expected it to kick to propane for trip, and honestly never checked on it. Got to CG, plugged in and fridge would not work. Even the light inside would come on for a moment then go back off. Checked fuses and breakers. After cycling the 110 volt breaker, the light would stay on, but still little cooling action. Stayed about 55 in fridge box, about 45 in freezer. It seemed to be doing some level of cooling.

There are three lights showing temp range on control panel. These flash a trouble code to alert you to problems. According to the manual, Light #1 (from left) by itself means problem in gas valve. Lights 1 & 2 mean overheating. Light #2 by itself means faulty temp sensor. Light #3 by itself means DC voltage issue. All 3 lights means control board problem. Mine is flashing Lights #2 and 3, which is not a code listed in the manual. I even called Dometic and the tech on the phone had no clue what that meant.

Anybody have any idea what this is?

I checked the following and all was OK:
12volt
110volt
fuses (both camper and internal on Fridge)
breakers
cycled power (both ac and dc separately and togeteher)
Plenty of propane.
camper was level.
No obvious hardware issues or connectors/wires loose.

I have not tried the unit on power at my house again yet, will do so tonight and update. Any ideas would be appreciated.

Tim

[Bama Rambler]

We've seen this before.
This thread had the same problem.

Here's the quote.

Manufacturer says they've seen this before with the right two lights. They say it's the same as the left two, and is an overheating condition.
A. Check the lp flu behind the fridge and ensure nothing is blocking (insulation or critters, bugs).
B. Reset the resetable fuse located on the flu itself (button is in between the 2 wires on the round sensor dealio).
No mo flashing lights...fridge is cooling down.

[Cowracer]

Originally Posted by Bama Rambler

We've seen this before.
This thread had the same problem.

Here's the quote.

Outstanding! I tried to search for it on FRF while camping but I was a bit overwhelmed by all the treads that returned from the search. I didn't get a chance to read them all, and I never thought to browse them when I got home.

I shall take a look at it just as soon as my happy butt gets home from work.

Thanks Bama!


Tim


P.S. It would have been real nice of Dometic to spend just an extra minute and add that little nugget of info to the manual.

[Bama Rambler]

Sometimes the search returns so many unrelated results that it's hard to sift through them. Glad I remembered it so I had a clue where to look.

[TimVWulp]

Is the fridge in a slide out? First camp out I went out on with mine had the same problem with fridge in slide out. found that the forced ventilation fans that are installed in the side out fridge were installed upside down. they were bowing the hot air down and out the bottom fridge access door. The fans should be blowing up and out the top door in the side wall.

Hope this helps Tim

[aceinspp]

Are you saying the frig will not work on either electric or gas? little confuse on that one. If its gas side and flashing normally it would be failed to light on gas when flashing. Try bleeding lines to get air out of system. Later RJD

[Cowracer]

So I finally had a moment to check the termofuse. It seemed to be in a 'reset' condition (I.e. it didn't feel like it had tripped). I pushed the button anyway, and powered up the fridge.


No change at all. Fridge is still INOP with that same trouble code. I'm at the point where I think I need to get the dealer involved.


Tim

[Bama Rambler]

It may be time to get service involved.

Did you check voltages across the thermofuse?
Did you check the glass fuses on the board?

[Cowracer]

Originally Posted by Bama Rambler

It may be time to get service involved.

Did you check voltages across the thermofuse?
Did you check the glass fuses on the board?

A) Not yet. My voltmeter was at work. I'll have to do it later
B) Yes. all fuses were good.

Tim

[2Evil4U]

The symptoms I've been seeing are slightly different. Interior light was intermittent. Frig would stop cooling occasionally but only on shore power. Flipping to gas would get it going again.

I fired it up on shore power last night. Everything was good this morning.

I pulled the covers off to inspect. Nothing seemed too bad, so I started jiggling the wires to make sure the connections were good. I found the main 12V supply wire was not tightened down in it's holder. It pulled out with no resistance.

While I was fiddling with that I also found that the bulk ground next to the 12V supply had an elastic stopnut installed upside down and it was completely loose so I had intermittent grounds as well.

I made a video which I'll have up shortly.

[Cowracer]

Fixed! Or at least problem found. Had no 12volt going to either side of the theromfuse in the flue pipe. I did have continuity thru the thermofuse, so that ruled that out. Had 12v on the wire going to the thermofuse at the circuit board connector.

The schematic showed a themal cut-off fuse in the circuit and after a brief search, i found it. Sure as hell, it had power going in, but none coming out. It had tripped and it's not resettable. For diagnostic purposes, i jumped around it and the fridge fault cleared and it started working. No idea why it tripped.

The dometic part is $38.00, but i found them at Frye electronics for $1.80. Got 3 coming, just in case. Hopefully it was just a fluky thermal cut-off.

Tim

[Bama Rambler]

Thanks for coming back and letting us know what you found. Especially the photos. That makes it real clear what and where the problem is.

[2Evil4U]

Very cool. Thanks for the update.