There should be a fuse in the fridge cable in the car. Have you checked that you have 12 volts at the fridge pin in the socket? Did the fridge work before with this car? It could be a fuse in the car or it could be a bad connection in the socket or plug, it's worth checking that before you start checking the fridge wiring.
What van do you have ie make model and year. What lead/leads are going to the car ?
if there are 2 from the van black and grey does your car have 2 sockets. If not and you are only plugging in the black plug the fridge won't run as, as far as I am aware the fridge runs off the grey lead
The 12v side of the fridge will only keep the temperature to the level it is when you start off. It takes a fair few miles of driving to tell if its working or not and it should only be working when you are driving and shut off when the engine is also off as it works on a relay.
many moons ago, when I had a little campervan, I thought the 12v bit wasn't working... I was stationery on the drive at the time and it wasn't until it was explained that you had to be driving that I found out it was working!
The caravan I have now doesn't have a 12v fridge system at all. What I do is to pack the fridge stuff from the fridge in the house, plus some frozen food and a few ice packs (the sort you get for a cool box) in on the day I'm going away. All is still cool when I get where I'm going, ready to use either on EHU or gas for the fridge when settled.
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