Dometic DM2852 making noise then quit

[forbesclan]

I have a 2011 Cyclone with a Dometic DM2852 fridge, its installed in the kitchen slide out.
Electrically the slide out has 2 110v AC outlets, one for the fridge and one for the microwave. Other than the 2 outlets, it has 4 small LED overhead lights.

My wife said the fridge started making noise (she described it as a squealing, grinding mechanical noise like a fan or motor) and the four LED lights started flickering. She pulled the 15A fuse labeled "slide" and the light flickering quit, the fridge noise eventually quit a few minutes later.

Now, the fridge does not work, no lights, no sounds, nothing. I checked the AC plug in the back of the fridge and I have power there and the "AC in" line going to the control board has power. Both fuses on the control board are good.

I can't tell if the in-line fuse in the red wire at the back of the fridge is good or not, it's a solid color where the glass usually is?

 

[danemayer]

Hi forbesclan,

Gas absorption refrigerators don't have motors or compressors that might make a squealing noise. There might be 1 or 2 fans on the back side to move air up and out the upper vent. If installed by the manufacturer, they would use 12V DC. When your wife pulled the fuse marked slide (presumably in the main fuse box), if the fans were the source of the noise, they, along with the refrigerator, would have immediately stopped running (and making noise) because 12V DC is necessary for the refrigerator control board as well as any fans.

You didn't mention putting the fuse back. I don't think the fridge will do anything without 12V DC, whether you have 120V AC or not.

 

[carl.swoyer]

Dane
Perfect answer

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[forbesclan]

Hi forbesclan,

Gas absorption refrigerators don't have motors or compressors that might make a squealing noise. There might be 1 or 2 fans on the back side to move air up and out the upper vent. If installed by the manufacturer, they would use 12V DC. When your wife pulled the fuse marked slide (presumably in the main fuse box), if the fans were the source of the noise, they, along with the refrigerator, would have immediately stopped running (and making noise) because 12V DC is necessary for the refrigerator control board as well as any fans.

You didn't mention putting the fuse back. I don't think the fridge will do anything without 12V DC, whether you have 120V AC or not.

Thanks for the info Dan, my wife is not sure now if it continued to run after she pulled the fuse, she did add that the flickering lights were dimming and acting as if they were losing power as the noise was occurring. Based on that I assume we lost DC power to the slide out slowly, over a period of time which caused the fan noise? If that is the case, could the inverter be the problem? We are plugged into 50A shore power and everything else is working properly.

The fuse was re-installed and it was not blown, however the overhead lights and the fridge still are not working, so I guess I either have a DC power problem that just happened to occur at the same time as a fan going out or the two are related. I have traced the electrical back to the junction box, everything looks good.

Today I will put a meter on the incoming DC power and see if I have 12V at the circuit board. Next step would be to replace the circuit board??

What are your thoughts??

 

[boatto5er]

Have you checked the voltage at your 12volt DC mini circuit breakers?


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[danemayer]

Thanks for the info Dan, my wife is not sure now if it continued to run after she pulled the fuse, she did add that the flickering lights were dimming and acting as if they were losing power as the noise was occurring. Based on that I assume we lost DC power to the slide out slowly, over a period of time which caused the fan noise? If that is the case, could the inverter be the problem? We are plugged into 50A shore power and everything else is working properly.

The fuse was re-installed and it was not blown, however the overhead lights and the fridge still are not working, so I guess I either have a DC power problem that just happened to occur at the same time as a fan going out or the two are related. I have traced the electrical back to the junction box, everIf thing looks good.

Today I will put a meter on the incoming DC power and see if I have 12V at the circuit board. Next step would be to replace the circuit board??

What are your thoughts??

1st thought: are other 12V DC devices ok? Furnace? Bathroom fan, other 12V DC lights? If so, you have a problem specific to the slide. The most likely cause is a damaged wire under the slide, possibly where it goes through the frame, or up into the floor of the slide. There also may be a junction box under the slide with a 12V DC connection that's loose. Check those.

2nd thought: If everything is acting funny, then if you have auto leveling, cycle the control panel to see what voltage is showing. While on shore power, it should be 13.2V at minimum and at times higher. Also check the tank level monitor. The test button displays not only tank levels, but also the 12V DC level (highest of batteries, power converter, or connected tow vehicle). While on shore power all 4 lights should light up when you press TEST.

If either of these is not true, you have a 12V DC problem in general. If 4 lights on the test, but less than 13.2V on the levelup panel, your 12V DC mini-circuit breaker near the battery is tripped. You need to fix that (easy), but the power converter should still be supplying 13.2V inside the coach and to the fridge.

Let us know what you find.

 

[forbesclan]

1st thought: are other 12V DC devices ok? Furnace? Bathroom fan, other 12V DC lights? If so, you have a problem specific to the slide. The most likely cause is a damaged wire under the slide, possibly where it goes through the frame, or up into the floor of the slide. There also may be a junction box under the slide with a 12V DC connection that's loose. Check those.

2nd thought: If everything is acting funny, then if you have auto leveling, cycle the control panel to see what voltage is showing. While on shore power, it should be 13.2V at minimum and at times higher. Also check the tank level monitor. The test button displays not only tank levels, but also the 12V DC level (highest of batteries, power converter, or connected tow vehicle). While on shore power all 4 lights should light up when you press TEST.

If either of these is not true, you have a 12V DC problem in general. If 4 lights on the test, but less than 13.2V on the levelup panel, your 12V DC mini-circuit breaker near the battery is tripped. You need to fix that (easy), but the power converter should still be supplying 13.2V inside the coach and to the fridge.

Let us know what you find.

Every other DC component is working except the 2 overhead lights in the other main room slideout. Overhead lights throughout the rest of the rig, furnace, fans, ect.. all work fine.
The junction box on the frame under the slideout has only AC wires in it. Conduit runs through the frame next to this box and carries 2 sets of 2 wire running to the back of the fridge. One of these has 0 VDC, the other set reads .3 VDC at the circuit board (obviously a problem)

Other info: No auto level, All 4 lights on Batt test light up. 13.26 VDC at the battery and on the bus bar next to the batt switch, 13.26 VDC into and out of the mini CB. 13.26 VDC at the fuse panel in the coach.

It looks like it must be a wire on the way out to the slideout.

Why don't these problems present themselves in nice weather when you have nothing else going on???
We have 2 feet of snow on the ground and its supposed to be a high of 27 F today!!

 

[danemayer]

Every other DC component is working except the 2 overhead lights in the other main room slideout. Overhead lights throughout the rest of the rig, furnace, fans, ect.. all work fine.
The junction box on the frame under the slideout has only AC wires in it. Conduit runs through the frame next to this box and carries 2 sets of 2 wire running to the back of the fridge. One of these has 0 VDC, the other set reads .3 VDC at the circuit board (obviously a problem)

Other info: No auto level, All 4 lights on Batt test light up. 13.26 VDC at the battery and on the bus bar next to the batt switch, 13.26 VDC into and out of the mini CB. 13.26 VDC at the fuse panel in the coach.

It looks like it must be a wire on the way out to the slideout.

Why don't these problems present themselves in nice weather when you have nothing else going on???
We have 2 feet of snow on the ground and its supposed to be a high of 27 F today!!

Does seem to be the kind of problem that shows up in monsoon season or when there's a 3 day blizzard. I assume you took voltage readings with the common lead of the meter on a known good ground. If so, you're chasing a problem with the hot wire, not a ground wire.

 

[forbesclan]

So I still have the same problem with DC power to both slide outs in the main living area. DC power feeds two lights in one slide out and four in the other along with the fridge. As a temporary fix I ran wire from the hot battery buss to the fridge, so it has been working, but none of the lights in either slide. I finally have some time to track down this problem, but so far no luck. This is where I am at so far:

The wires running from the fuse box labeled "slide" are blue/white, but all of the wires in the slide outs to the inop components are green/white, it seems to me they would have kept the same color of wire from panel to component? Keep in mind the labels are hand written and I don't know wrote them, so they could be wrong. I do have 3 separate circuits with wires that are green/white leaving the fuse box, I have traced these as far as I can without major disassembly and have found no damage, all of these have 13.2v at the fuse box.
There are two hots and two grounds running to the fridge (both green/white), I assume one is the supply and the other continues on to supply the lights. One of these tests a little over 7v on a multi-meter the other 0. I'm guessing the one with zero continues on to supply the lights.

My question is; if I have lights out in two different slide outs on different sides of the camper, it seems my damage/ loose connection would be before they split and go to different sides of the rig, but I see no evidence of this. Also, what would cause me to have only 7v at the wire to the fridge? Could that be a partially damaged wire? I thought that even if only one strand was intact it would still measure the full voltage, it might not carry the current under load, but as far as a voltage test it should appear fine? Am I mistaken on this?

If anyone has had a similar problem and found a solution, or have any thoughts on where the problem might be, please let me know. Thanks!