Dometic Refrig problem

I want to thank everybody for their input on this issue with the Dometic refrig. After using all your ideas to try and find what was wrong it came down to the circuit board. Thanks to everybody.

DB

Usually, the Converter/Charger unit is powered by 120VAC from Shore Tie. When plugged in it charges the House Battery. It also disconnects the House Battery from the 12VDC loads in the coach and powers them with 12VDC that it produces independently of the battery charge portion. Unplug from Shore Tie and the Converter re-connects the House Loads direct to the Battery.
BUT... it's always possible to connect a 12VDC load directly to the Battery. The Battery is always that load's power source. May or may not be getting charged, but the Battery's still the source.
A Battery provides cleaner, smoother power than a Converter (at least than the older ones) and some Fridge Install Instructions wanted the power source to be Direct from Battery. I mention this because it might be how your coach battery powers the logic board in your fridge. That could simplify things, but it might raise different issues about how it's grounded.

The ground, not neutral, on the 120 volt and the 12 volt is the same, chassis frame. Perhaps the refrigerator is getting it's 12 volt ground from the 120 volt ground through the 120 volt cord when plugged in. So look for a bad 12 volt ground, ether where it gets it's 12 volt or at the circuit board.

Dusty

Ours when hooking and unhooking power causes problems. Often the check light comes on but sometimes doesnt. Make sure it is set to auto and the second button is depressed to automaticically change over.

Check fuses in the frige control board. I had same problem which turned out to be the 3 amp fuse.

enblethen wrote:
Does all the other 12 volt DC items work?
Lights? Furnace?

All 12 volt items work fine.

Does all the other 12 volt DC items work?
Lights? Furnace?

Whenever I have an unusual problem in an electrical system , such as this I would check and double check the grounds. Bad ground connections cause some crazy problems.

Cleaned all 12 volt connections, the voltage when hooked to shore power and the refrig unplugged from 110 outlet is 13.70 and when shore power is disconnected the voltage is 13.04. I wouldn't think this drop in voltage would have an cause the problem. Any other ideas?

DB