Hello Ray,
In 1984, most caravan lights we designed to run off the 12V dc supply, not mains (there are some exceptions but tended to be the Carlights & Castletons etc.
So obviously theres should be a battery on board, and perhaps a charging system.
The Mains supply should come in through some form of distribution box, and even in 1984, would be fitted with circuit breakers or fuses rather like a smaller version of the domestic fuse box. These should be checked.
As emmerson points out, the fridge may not include a 230V system, or even at 20 years old it may of course be faulty.
I do not wish to offend, but as you have posted this question on this forum, it suggest to me that you may not have the knowledge to resolve your difficulty. As 230V ac is dangerous if incorrectly used, my advice would be to seek the help of a competent electrician to diagnose and effect repairs.