Caravan Fridge and Air Conditioning Darwin

There are a few things that could be causing this, but it's usually due to not enough liquid ammonia being produced. Start by checking that the fridge is level and there's sufficient ventilation. If neither of these solves the problem, it's likely to be a fault with the cooling unit. 

The fridge should take about 12 hours to reach 4 degrees when it's on full cooling power. If you tow on 12 volts for two hours, the fridge will reach 14 degrees inside and will take another 12 hours or so to cool down properly.

Yes. A caravan fridge, unlike a regular fridge, relies on gravity to keep the contents cold. If it's not level, it will have to work harder to keep the contents cold, which makes it less energy efficient.
 
Most caravan fridges also have absorption cooling features. This means that there are no moving components within, ensuring that the fridge won't be damaged if it's shaken during travel. To put it another way, caravan refrigerators are better built to withstand the bumps and grinds of the road.

One of the many concerns that caravanners have about their A/C equipment is whether it can be run on battery power. Theoretically, you can use a battery, but it's not practical to do so. It's best to use an electrical hookup once you reach your destination.

Yes, and manufacturers recommend your air conditioning is regassed every two years. If you use your air conditioning on a regular basis, you may need to perform the process more often (annually or even every six months).

There can be a number of reasons why no heat is coming from the vents of your A/C. Start off by checking that the ducts and coils aren't blocked - if you've not used your caravan in a while, dust and debris may have built up in the filters. If this doesn't work, you may have a damaged circuit breaker or fuse, which will need to be repaired by a professional.