Dometic refrigerator troubleshooting - thermo breaker failure

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Dometic refrigerator troubleshooting - thermo breaker failure

July 19, 2018, 07:33:27 pm

We are up at a boondocking campground about 5k in elevation. This is our 4th night here. Our 2017 RB is less than 1 year old. We have 2/3 f ull tank of LP. Everything has been working very well untill 30 minutes ago when refer stopped working. Stove still has gas, all other electrics in coach working fine. Outside tmps are 80 to 90 degrees. Control panel does not ghts up, but fridge will not light. I checked fuses. All good. Anyone have a suggestion?

Re: Brand new Dometic quit running on gas mode

Reply #1 – July 19, 2018, 07:40:07 pm

Are you able to manually switch the frig to gas rather than using the automatic switch?

Re: Brand new Dometic quit running on gas mode

Reply #2 – July 19, 2018, 07:41:04 pm

There are additional fuses to check in the back of the fridge, outside access door.

Steve

Re: Brand new Dometic quit running on gas mode

Reply #3 – July 19, 2018, 07:55:07 pm

Checked all fuses in rear (outside) and checked panel inside. All ok. Replaced with new fuses, problem persists. No power at all to control panel above freezer. We have LP. Interior refer light is also off. Plugged/unplugged 120 outlet several times. No cure. Bad control panel? Rig was picked up new in January. Have had no issues until now. We have been up here four days. All has been good until refer quit.

Re: Brand new Dometic quit running on gas mode

Reply #4 – July 19, 2018, 08:08:17 pm

If a voltmeter check shows 12V at the rear of fridge, then the fridge control panel has failed.

Steve

Re: Brand new Dometic quit running on gas mode

Reply #5 – July 19, 2018, 08:21:09 pm

Does the “control panel” have a separate circuit board from the refrigerator’s?

Re: Brand new Dometic quit running on gas mode

Reply #6 – July 19, 2018, 08:26:31 pm

Steve -- I did check the 120 v circuit. That is live (in back of refer). Where would I rest the 12v? I do have a volt meter.

Re: Brand new Dometic quit running on gas mode

Reply #7 – July 19, 2018, 08:31:16 pm

I was camping at about 7,000 ft a couple of years ago....had to clean the burner tube...then all was good with the world...

Re: Brand new Dometic quit running on gas mode

Reply #8 – July 19, 2018, 08:54:29 pm

Thank you all for fast responses. We are getting very limited Internet connection. My replies may thusly delayed.

Re: Brand new Dometic quit running on gas mode

Reply #9 – July 19, 2018, 09:22:37 pm

Steve and Joan, I am assuming that when you mentioned the refrig. control panel, you meant the circuit board that is on the back of the refrig. Mine failed 6 months after I took delivery. It was replaced under warranty and is still going. So, a component on a circuit board failing when relatively "young" is not unusual. That is why critical systems are often powered up and run for a while before being installed.

Bottom line - turn the refrig. on and use your voltmeter to look for 12 volts on any of the wires coming into the circuit board. Do so by disconnecting them and touching each wire with the voltmeter probe. If none have 12 volts, you have either a bad switch, a bad fuse or a bad connection somewhere. There is even a chance that you have a bad wire. (I know of someone who drove a screw through a wire. It worked for a while, as the screw completed the circuit, so he did not suspect wire damage. It took him a while to find that one.) If you do have 12 volts coming to the board, and the refrigerator will not run, and all the contacts on the board are clean, you probably have a bad circuit board.

Ken F in WY

Re: Brand new Dometic quit running on gas mode

Reply #10 – July 19, 2018, 09:34:08 pm

i wasn’t aware of a “known problem” with Dometic refrigerators not running well on LPG above 5000’, maybe because I’ve never had an issue in 15 years of boondocking with the refrigerator running on propane in elevations *well* over 5000’.

This scenario could certainly change at any time, of course! As ever, YMMV.

Re: Brand new Dometic quit running on gas mode

Reply #11 – July 19, 2018, 09:45:54 pm

Ray, you didn't mention what model fridge you have, but I'm guessing it may be an RM3762 or similar. If so, the Dometic service manual is available online in PDF format. It's about 3 megabytes, so it may be a problem for your slow internet connection, but if you can grab it, it'll give you some things to look at. Good luck! By the way, I've used Dometic absorption fridges at upwards of 9,000 feet without a problem, so that 5,000' warning of theirs should be taken with a grain of salt.

Re: Brand new Dometic quit running on gas mode

Reply #12 – July 19, 2018, 10:01:35 pm

All -- our 6 month old Dometic is a model number DM 2662. This will be the 4th trip to this same location since we took ownership. I have never experienced a problem here in the past, and we had Dometics in our Winnebagos. That said, it is beginning to s ound like a fuse or circuit board problem. We have decided to leave in the morning (just one day shorter than planned) and I will seek a warranty service on it when we get back to the Bay Area. I will post results accordingly. Thank you all again for weighing in on our "panic call" and I hope the fix is simple. Standby for more in coming days or weeks.

Re: Brand new Dometic quit running on gas mode

Reply #13 – July 19, 2018, 10:13:38 pm

Ray,

If I understand you correctly, the “eyebrow” on the top of the fridge inside the coach (not outside behind the access door) does not light up.

I’ve blown the main fuse to our ‘15 RB fridge twice trying to install a circulation fan. Haven’t figured that part out yet but I was able to replace the fuse inside the black box accessed from the outside access panel.

You’ve probably checked here already but there it is. Good luck.

Here’s a pic of the box I’m talking about. There are two fuses inside. The upper left fuse (3amp) is the one I’ve blown and replaced.

Kent

Re: Brand new Dometic quit running on gas mode

Reply #14 – July 19, 2018, 10:20:28 pm

Kent.... how do you access the fuses in that black box? Do you remove that screw at the top of the black box?

Re: Brand new Dometic quit running on gas mode

Reply #15 – July 19, 2018, 10:40:44 pm

Ed,

There is one Allen acrew on the top/center of the box. Remove it. On the bottom corners (left and right) is a tab/slot to insert a small flat screwdriver. With a little force wedge the right tab out to the right to release the tab. Do the left side tab but wedge it’s tab to the left.

Once this has been done (kinda freaks me out a bit cause I don’t want to break the tabs, but I haven’t yet) simply lift the box front off. It snaps back on easily when you’re done.

On our Dometic (probably the same as Ray’s) the fuse I’ve blown is the shorter 3amp fuse on the left. The fuse to the right is a bit longer and I’ve never had to mess with it.

I keep spare fuses in a zip lock bag velcro’ed to the left wall in the back fridge access area. Here are some pics.

Kent

Re: Brand new Dometic quit running on gas mode (refrigerator troubleshooting)

Reply #16 – July 19, 2018, 11:05:43 pm

The fact that in a period of 3 hours seven members chimed in to help Ray with his refer problem is what this group is all about. Help is there when you REALLY need it. Nice work.

Chris

Re: Brand new Dometic quit running on gas mode (refrigerator troubleshooting)

Reply #17 – July 19, 2018, 11:11:17 pm

Quote from: Ray S. - July 19, 2018, 08:26:31 pm

Steve -- I did check the 120 v circuit. That is live (in back of refer). Where would I rest the 12v? I do have a volt meter.

The 12V supply is also at the back.

Steve

Re: Brand new Dometic quit running on gas mode (refrigerator troubleshooting)

Reply #18 – July 20, 2018, 01:20:18 pm

I recently had the dash in my Avalon go out of wack. First the car wouldn’t start. Tightening the battery terminals got the dash to show some life but was acting strangely.

While sitting still, the Speedo showed I was going 72 mph, temp was through the roof and I had a full tank of gas. Very strange behavior since three hours earlier everything was working fine and had never behaved this way before.

I took it to my local Auto Repairman and it turned out to be dirty battery terminals causing the trouble. After cleaning the terminals and tightening them down, all was right with the world. John, my mechanic, tested the battery and alternator and they were fine as well.

The moral of this tale: A loose or dirty connection can sometimes be the blame for electronic abnormalities.

Just sayin’

Kent

Re: Brand new Dometic quit running on gas mode (refrigerator troubleshooting)

Reply #19 – July 20, 2018, 04:36:25 pm

Ken had got it right. Bottom line - turn the refrig. on and use your voltmeter to look for 12 volts on any of the wires coming into the circuit board. Do so by disconnecting them and touching each wire with the voltmeter probe. If none have 12 volts, you have either a bad switch, a bad fuse or a bad connection somewhere.

You are not getting 12v to the eyebrow control board. You know that because no lights are on. [Elevation is a distraction, if it quit due to elevation the lights would be on]

In Kent's first picture of the "black box" outside behind the refer the larger lugs (red and white) are from the circuit board in the rig. Is there 12v there? No, then the problem is between there and the circuit board. You checked the fuses, check the wires on the board going to the refer - are they tight?

If you have 12v at the red and white lugs, check the smaller wires to the left of the large lugs - yellow and black. 12v there? Yes, the black box is OK and the problem is between there and the eyebrow arch.

There is a high temp cutout on the "smoke stack" is it connected? You should also read 12v between there and ground.

That's all I can think of. It's a good drill for all of us to do, to see where 12v lives while it's working for reference when it's not.

Re: Brand new Dometic quit running on gas mode (refrigerator troubleshooting)

Reply #20 – July 21, 2018, 07:43:08 am

There is a thought that came to mind while reading this over, you said you had been out for 4 days, could it be that your batterys are low enough that they will run coach lighting but not the electronics in the friges control boards?
I'm guessing you would need a pretty solid 12+ volts to the frige. Will it run on 110 Volts from the generator?

Re: Brand new Dometic quit running on gas mode (refrigerator troubleshooting)

Reply #21 – July 21, 2018, 12:01:59 pm

Good morning, all! We returned home late last evening, and I did not fool around with the problem yesterday during our transit. I am going today with a better set of auto-electric tools and probes, my iPad and this excellent thread, and a couple of YouTube vids to thoroughly and systematically check things out. I will report the outcome later today.

As for a couple of points already brought up in this thread, yes, the "eyebrow" and the interior refer light are not powered. The interior refer fuse is good, and I had a spare that I used that did not help. The other coach electrics are working well. The solar panels were fully charged daily by several hours of direct sun, and several more of indirect. In fact, after the refer quit, we ran two small inverters to charge our phones, ran the roof vent fans, and watched 2-hours of TV that evening with no electrical malfunctions. The lowest voltage displayed on the solar control was 12.9, and that was just as we went to bed about 10:00 pm. In the morning, the display read in the mid-13s and then we hit the road for the trip home. At the storage facility, the display was reading 14 and change.

Logic (and the people on this thread) tells me that it is a fuse or loosened wire. I am hoping nothing more involved. I will report in later.

Once more, your responses are greatly appreciated.

Re: Brand new Dometic quit running on gas mode (refrigerator troubleshooting)

Reply #22 – July 21, 2018, 08:34:02 pm

Sorry for delay. Grandkids popped in unexpectedly for a late lunch. Anyway, here is the result of today's investigation.
1) 12V power is good to the control panel inside the coach. All circuits lit up the tester.
2) The tester showed good 12V from the interior panel to the control module block in the rear of the refer (checked from the outside).
3) Tester showed that the 5A glass fuse on the control module was good.
4) Tester showed NO power at all on the control module, tested at several 12V connections as well as the "Test" point on the board itself.
5) Started gennie and tested both 120V outlets. All good.
6) All other coach electrics working normally.
Conclusion: Bad control module. I will contact Dometic Monday and confer, then seek closest recommended service center for a warranty repair.

Thank you all for helping on this. Very frustrating. Not untypical, in my experience. In all of our RVing experience, the appliance that has given us the most trouble over all are the refers. Delicate pieces of equipment. In fact, we had to replace our NorCold with a Dometic in our last Class C Winnebago. So, not new to this sort of hassle, just never had it crop up on such a new rig.

Re: Brand new Dometic quit running on gas mode (refrigerator troubleshooting)

Reply #23 – July 22, 2018, 07:38:19 am

Thanks for the update, Ray. If I were in your shoes, I'd get a Dinosaur ignitor board and install it myself (not a big deal). For a little over a hundred bucks, I'd have a much more reliable controller board. Over the years I've seen scores of stories of OEM boards failing, but I've never heard of a Dinosaur board failing. Just my two cents' worth.

Re: Brand new Dometic quit running on gas mode (refrigerator troubleshooting)

Reply #24 – July 22, 2018, 05:12:30 pm

Quote from: Andy Baird - July 22, 2018, 07:38:19 am

If I were in your shoes, I'd get a Dinosaur ignitor board and install it myself (not a big deal). For a little over a hundred bucks, I'd have a much more reliable controller board. Over the years I've seen scores of stories of OEM boards failing, but I've never heard of a Dinosaur board failing. Just my two cents' worth.

X2
Dino boards are the 'go to' solution to blown control boards for the refrigerator, furnace and water heater.
Many times, the Dino boards are cheaper too.
The refrigerator Dino board is an easy install, just swap the wires and then screw the cover on, literally a ten minute job.

Our stock refrigerator and water heater boards years ago were changed out years ago. The original boards are carried as spares.
Our old refrigerator and water heater boards has been loaned out several times during the years, at Caravans and other GTGs, where someones refrigerator or water heater has failed.

Larry

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