Frig not working on AC

[twinster2]

After investigating my two-way refrigerator, I determined that it runs fine on LP but not on AC when shore line power is available. I used a volt meter to check voltages and found none going to the heating element. I also checked the heating element and found it had the correct resistance, so I concluded that the lower control board was shot. Ordered one on Amazon and the shipping date was originally in early October. To my surprise, it arrived last Friday. I installed the new board and still did not get any voltage going to the heating element. So now I wonder if the board I recieved is a previously returned item from another customer because it does not work. Anyway, I returned the new board and will rely on LP too cool the frig dow.

[Eagle]

I just leave my frig on "auto" so it can switch between propane and AC when AC is available....at least that is how I undertand 'auto' works.
Please correct me if in error.
Sorry, this does not solve your issue however.

[APD]

This is what I found. Hope this helps: https://fourwheelcampers.com/NewDome...atorManual.pdf

[bigjohnsd]

Originally Posted by APD

This is what I found. Hope this helps: https://fourwheelcampers.com/NewDome...atorManual.pdf

Thanks very much for posting this link, it helped me trouble shoot my refer.

[E4BAEROSPACE]

Originally Posted by bigjohnsd

Thanks very much for posting this link, it helped me trouble shoot my refer.

What he said ^ Thanks!

[twinster2]

Problem solved. It was the upper control board that was the problem. Funny how the diagnostics tell you to replace the lower control board at a cost of $100 and don't mention that the upper control board at a cost of about $30 will solve the problem. I grateful that amazon allowed me to return the lower board. Anyway for those that are having problems with your refrigerator not running on AC, and have diagnosed that it's not the fuse or heating element, you may want to replace the upper control board first.

[RipVan]

Originally Posted by Eagle

I just leave my frig on "auto" so it can switch between propane and AC when AC is available....at least that is how I undertand 'auto' works.
Please correct me if in error.
Sorry, this does not solve your issue however.

This is how I use my Dometic frig too! On the control panel, there is a "CHECK" indicator that "lights up" when the frig isn't functioning properly. My experience has been this occurs when the trailer isn't level (like really unlevel &#128528 but I wonder if it signals a problem with other components like the upper or lower control boards?
The OP didn't mention just how he realized that his frig wasn't working (beyond the obvious of not getting cold) 🙄. I may have to test my AC function by turning off the propane tank, leave the "shore power" hooked up and wait to see if the CHECK light comes on or the frig fails to stay cold.
It's only marginally related to the OP's dilemma but in the "AUTO" mode with both AC and propane available, does one take priority over the other? I guess if I was the design engineer, I would make AC be the primary mode in order to conserve propane 🤔. IDK

[twinster2]

Let me clarify this a bit. The frig stopped working on AC when it was set to "auto" mode and plugged into shore line power. It would only work on LP in the "auto" mode. If the gas was turned off in this configuration it would go to a check mode and no longer cool. Diagnostics indicated it was a bad lower control board. However replacing the lower control board did not solve the problem. I returned the lower control board and purchased the upper control board. Replacing the upper control board solved the problem and was a much cheaper fix. Moral to this thread is if your frig is not working on AC in the "auto" mode and you have checked the AC power supply, fuses and electric heating element, the problem might be the upper control board.

[APD]

Glad you got the problem solved. Nothing kills a good day like coming back to the camper after site seeing to find a warm fridge. We've never tried the propane on ours, always used the shore power.