Last week I noticed that our fridge freezer in the Hymber (B544 Premiumline 2016) was not changing over from gas power to 12v when the engine was running. I checked briefly and found that the change from gas to 240v worked correctly when I plugged in the hook cable.

Fault diagnosis is ongoing. First I checked all the fuses on the Hymer’s electrical panel, a lot of fuses, but non of them was blown.

Next came some internet searching to review what other people had experienced. My first guess is that the 12v heating element is not working. That means either there is no power getting to it, or the 12v heating element is damaged, blown but simply open circuit.

I’m waiting for a fine day to do some more checks with a test meter, I’ll update this post as soon as I know more.