Dometic RM2862 no panel lights

[foszoe]

Hi,

Just picked up a used 2007 Copper Canyon with the Dometic RM 2862 refrigerator at a dealer. The dealer had everything hooked up and running on AC but also had a battery charger hooked to the battery because the 12V was dead. Everything worked. Fridge was cooling. It was an as is sale.

Got home and the next day I wanted to run it on propane to see how it worked. It would not start. I checked fuses and found one blown but not labelled anything obvious like "fridge".

I swapped out the fuse and also took the battery out while disconnected to charge it. When I put the battery back in, the fridge started up and ran for 5 hours cooling down slowly but steady enough. So I shut it off.

At first I was thinking the fuse was the issue but then read manuals talking about the importance of voltage so I went out and tried to turn on the fridge. It didn't come on. The voltage at the battery was 9.2 and by the time I got to the back of the fridge it was in the 8s. Ah ha I said!. It's a voltage issue. I swapped the battery out and the same mysterious fuse in the power center blew. I replaced it. Now I had 12.54V at the battery and 12.37 at the back of the fridge. I go inside and hit the on/off button....nothing.

I checked the thermofuse button I had read about and it could not be pushed in. I disconnected the battery and disconnected the wires to the thermofuse. The reset button now moved in and out quite easily and the thermofuse continuity check passed.

Now I am stuck. Anything I have missed? What are next steps?

Thanks for any help!

 

[Henry J Fate]

I am fairly sure there is a fuse on the control board. There Should be two fuses. One of them is the 12 volt fuse.

 

[foszoe]

You are right. There is a 3A fuse on the control board. It checked out ok but I replaced it anyway because fuses are cheap.
The manual said check for voltage on P1 connectors 4 and 5 f(red and orange). That connector is between the upper eyebrow panel and the lower control panel. I showed a zero voltage when I stuck the probes on those two pins. That would seem to say that the lower control board is bad according to the manual.

I hope someone else with more experience agrees as I am just reading the manual w/o any.

I was wondering if I could bypass all the controls to see if the refrigerator at least cools. Then I could be certain it was the board.

 

[Henry J Fate]

No voltage at the test point would not determine a bad board on it's own merits. I don't have the test specification but will assume that it is possible that the lack of 12 volts could be interrupted prior to that board.

First test would be to varify if 12 volts is being delivered from the 12 volt service panel. From there the 12 volts should be followed to determine where it suddenly disappears.

 

[foszoe]

There is definitely 12 V available at the refrigerator.

 

[Henry J Fate]

It's possible the board went bad shortly after leaving the dealer. Just seems unlikely timing as you said it was cooling at the dealer. Maybe it is time to look for a replacement.

 

[Gary RV_Wizard]

You can easily bypass the control board for 120vac mode but not so easily for gas operation.

For 120vac mode, simply connect the pair of wires of the heater element direct to 120v input wiring, bypassing the board altogether. There is no thermostat control once you do that, so don't leave it connected for a lengthy period.  Once you verify that the boiler is heating and the fridge interior cooling, disconnect it.

 

[foszoe]

https://www.amazon.com/gp/product/B0002FRCD6/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1

That is what it was. Replaced it and it worked fine!