Checking out DM2862 Fridge

[Coloradjoe]

I bought a used DM2862 and it doesn't even try to get cold. I checked the heating element and the thermistor, and they are within spec. With 12VDC and 120VAC connected, and the fridge OFF, I get 12V across the orange and red in P1. I get NO voltage between J1 and J10 or J4 and J10. I do get voltage between the red and orange on the upper board, with power ON.
These tests were done with the thermistor disconnected.
The board number is 50-965201-D, which crosses to a Dinosaur 3850712.01.
The Diagnostic Service Manual doesn't say what these results mean.
Do I need a new lower board?
Thanks.
Joe in Colorado

[cadman99]

How long did you wait for it to get cold???

Will it work on propane??

[Coloradjoe]

It is not in the RV, so I have not connected to propane. I waited two days for it to get cold.
Thanks.
Joe

[cadman99]

Well I would hook it to propane - This way you will know if it works or not.

The propane heat is simple and supplies faster cooling than the electric unit.

It is possible the frig is toast - but you won't know until you get enough heat for it to try and work. The whole principal is simple - heat the ammonia and the frig works.

Essentially you are trying to bypass the circuit board to see if the basic frig even works.

[Herk7769]

Originally Posted by Coloradjoe

It is not in the RV, so I have not connected to propane. I waited two days for it to get cold.
Thanks.
Joe

Is it hooked up to 12 volts? Just plugging it in only works the heating element and does not produce the required 12 volts DC to run the control panel.

Connect a battery to the DC inputs and then plug it in.
Press "AUTO"

[Coloradjoe]

Yes, 12V Is Connected.
I'm Going To Try To Connect A Bbq Grill Hose To It.
Thanks
Joe

[Herk7769]

OK, next you need to check the 120 VAC fuse.

You should also look for a yellowish stain anywhere around the coils, especially in the lower right side (the boiler).

If there is a leak here you will need a new coil set.

[Herk7769]

This may also help

RV Refrigerator Troubleshooting - YouTube

If it turns out you need a coil replacement, here is one place.
I have not done business with them.

http://www.rvcoolingunit.net/servlet/StoreFront

[Coloradjoe]

Thanks. The fuses were checked out first, and are ok.
The heating element has continuity.
I did all the tests mentioned in the Diagnostic Service Manual.
There is no evidence of past leakage on the back. In fact, the fridge is only 4 years old, and looks new all over.
It has been cold and snowy here, and I've not gotten to pulling a hose from a grill so as to check out the propane system.
An answer to my original question about lack of voltage between J1/J4 and J10 would be appreciated.
When I set the fridge on Auto, the gas part does click.
Thanks for the help.
Joe

[Herk7769]

Cold and Snowy? Is the fridge outside?

Is is possible the outside air temp is below the thermistor setting?

Push comes to shove, a control board may be your next move (or call Dometic Tech Support for a suggestion).

Replacement boards for Dometic

Contact - Dometic

[cadman99]

I don't think the thermistor is an issue. When they fail the frig runs all the time and becomes a big freezer.

[Herk7769]

Originally Posted by cadman99

I don't think the thermistor is an issue. When they fail the frig runs all the time and becomes a big freezer.

Not what I was driving at. If the outside air is colder than the fridge temp setting, it will not "run" in either DC/propane or DC/AC.